- 21 Nov, 2024 1 commit
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Ozan Tezcan authored
Starting from https://github.com/redis/redis/pull/13133 , we allocate a jemalloc thread cache and use it for lua vm. On certain cases, like `script flush` or `function flush` command, we free the existing thread cache and create a new one. Though, for `function flush`, we were not actually destroying the existing thread cache itself. Each call creates a new thread cache on jemalloc and we leak the previous thread cache instances. Jemalloc allows maximum 4096 thread cache instances. If we reach this limit, Redis prints "Failed creating the lua jemalloc tcache" log and abort. There are other cases that can cause this memory leak, including replication scenarios when emptyData() is called. The implication is that it looks like redis `used_memory` is low, but `allocator_allocated` and RSS remain high. Co-authored-by:
debing.sun <debing.sun@redis.com>
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- 08 Oct, 2024 1 commit
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Oran Agra authored
INT_MIN value must be explicitly checked, and cannot be negated.
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- 08 Sep, 2024 1 commit
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Ozan Tezcan authored
#13495 introduced a change to reply -LOADING while flushing existing db on a replica. Some of our tests are sensitive to this change and do no expect -LOADING reply. Fixing a couple of tests that fail time to time.
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- 16 Jul, 2024 1 commit
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debing.sun authored
Nowdays we do not trigger LUA GC after loading lua script. This means that when a large number of scripts are loaded, such as when functions are propagating from the master to the replica, if the LUA scripts are never touched on the replica, the garbage might remain there indefinitely. Before this PR, we would share a gc_count between scripts and functions. This means that, under certain circumstances, the GC trigger for scripts and functions was not fair. For example, loading a large number of scripts followed by a small number of functions could result in the functions triggering GC. In this PR, we assign a unique `gc_count` to each of them, so the GC triggers between them will no longer affect each other. on the other hand, this PR will to bring regession for script loading commands(`FUNCTION LOAD` and `SCRIPT LOAD`), but they are not hot path, we can ignore it, and it will be replaced https://github.com/redis/redis/pull/13375 in the future. --------- Co-authored-by:
Oran Agra <oran@redislabs.com>
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- 11 Jul, 2024 1 commit
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debing.sun authored
The`Scripts do not block on waitaof` test keeps failing in the external CI: https://github.com/redis/redis/actions/runs/9875670156/job/27272955900?pr=13407 The main reason is that if AOF happens to be enabled, we get an acklocal of 1.
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- 13 Mar, 2024 1 commit
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Binbin authored
In some cases, users will abuse lua eval. Each EVAL call generates a new lua script, which is added to the lua interpreter and cached to redis-server, consuming a large amount of memory over time. Since EVAL is mostly the one that abuses the lua cache, and these won't have pipeline issues (i.e. the script won't disappear unexpectedly, and cause errors like it would with SCRIPT LOAD and EVALSHA), we implement a plain FIFO LRU eviction only for these (not for scripts loaded with SCRIPT LOAD). ### Implementation notes: When not abused we'll probably have less than 100 scripts, and when abused we'll have many thousands. So we use a hard coded value of 500 scripts. And considering that we don't have many scripts, then unlike keys, we don't need to worry about the memory usage of keeping a true sorted LRU linked list. We compute the SHA of each script anyway, and put the script in a dict, we can store a listNode there, and use it for quick removal and re-insertion into an LRU list each time the script is used. ### New interfaces: At the same time, a new `evicted_scripts` field is added to INFO, which represents the number of evicted eval scripts. Users can check it to see if they are abusing EVAL. ### benchmark: `./src/redis-benchmark -P 10 -n 1000000 -r 10000000000 eval "return __rand_int__" 0` The simple abuse of eval benchmark test that will create 1 million EVAL scripts. The performance has been improved by 50%, and the max latency has dropped from 500ms to 13ms (this may be caused by table expansion inside Lua when the number of scripts is large). And in the INFO memory, it used to consume 120MB (server cache) + 310MB (lua engine), but now it only consumes 70KB (server cache) + 210KB (lua_engine) because of the scripts eviction. For non-abusive case of about 100 EVAL scripts, there's no noticeable change in performance or memory usage. ### unlikely potentially breaking change: in theory, a user can maybe load a script with EVAL and then use EVALSHA to call it (by calculating the SHA1 value on the client side), it could be that if we read the docs carefully we'll realized it's a valid scenario, but we suppose it's extremely rare. So it may happen that EVALSHA acts on a script created by EVAL, and the script is evicted and EVALSHA returns a NOSCRIPT error. that is if you have more than 500 scripts being used in the same transaction / pipeline. This solves the second point in #13102.
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- 10 Mar, 2024 1 commit
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Matthew Douglass authored
Since lua_Number is not explicitly an integer or a double, we need to make an effort to convert it as an integer when that's possible, since the string could later be used in a context that doesn't support scientific notation (e.g. 1e9 instead of 100000000). Since fpconv_dtoa converts numbers with the equivalent of `%f` or `%e`, which ever is shorter, this would break if we try to pass a long integer number to a command that takes integer. we'll get an implicit conversion to string in Lua, and then the parsing in getLongLongFromObjectOrReply will fail. ``` > eval "redis.call('hincrby', 'key', 'field', '1000000000')" 0 (nil) > eval "redis.call('hincrby', 'key', 'field', tonumber('1000000000'))" 0 (error) ERR value is not an integer or out of range script: ac99c32e4daf7e300d593085b611de261954a946, on @user_script:1. ``` Switch to using ll2string if the number can be safely represented as a long long. The problem was introduced in #10587 (Redis 7.2). closes #13113. --------- Co-authored-by:
Binbin <binloveplay1314@qq.com> Co-authored-by:
debing.sun <debing.sun@redis.com> Co-authored-by:
Oran Agra <oran@redislabs.com>
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- 22 Feb, 2024 1 commit
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debing.sun authored
Implement #12699 This PR exposing Lua os.clock() api for getting the elapsed time of Lua code execution. Using: ```lua local start = os.clock() ... do something ... local elpased = os.clock() - start ``` --------- Co-authored-by:
Meir Shpilraien (Spielrein) <meir@redis.com> Co-authored-by:
Madelyn Olson <34459052+madolson@users.noreply.github.com>
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- 23 Jan, 2024 1 commit
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Binbin authored
In #11568 we removed the NOSCRIPT flag from commands, e.g. removing NOSCRIPT flag from WAIT. Aiming to allow them in scripts and let them implicitly behave in the non-blocking way. This PR remove NOSCRIPT flag from WAITAOF just like WAIT (to be symmetrical)). And this PR also add BLOCKING flag for WAIT and WAITAOF.
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- 12 Oct, 2023 1 commit
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zhaozhao.zz authored
In #11568 we removed the NOSCRIPT flag from commands and keep the BLOCKING flag. Aiming to allow them in scripts and let them implicitly behave in the non-blocking way. In that sense, the old behavior was to allow LPOP and reject BLPOP, and the new behavior, is to allow BLPOP too, and fail it only in case it ends up blocking. So likewise, so far we allowed XREAD and rejected XREAD BLOCK, and we will now allow that too, and only reject it if it ends up blocking.
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- 05 Aug, 2023 2 commits
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zhaozhao.zz authored
Fix the assertion when a busy script (timeout) signal ready keys (like LPUSH), and then an arbitrary client's `allow-busy` command steps into `handleClientsBlockedOnKeys` try wake up clients blocked on keys (like BLPOP). Reproduction process: 1. start a redis with aof `./redis-server --appendonly yes` 2. exec blpop `127.0.0.1:6379> blpop a 0` 3. use another client call a busy script and this script push the blocked key `127.0.0.1:6379> eval "redis.call('lpush','a','b') while(1) do end" 0` 4. user a new client call an allow-busy command like auth `127.0.0.1:6379> auth a` BTW, this issue also break the atomicity of script. This bug has been around for many years, the old versions only have the atomic problem, only 7.0/7.2 has the assertion problem. Co-authored-by:
Oran Agra <oran@redislabs.com>
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sundb authored
This PR mainly fixes a possible integer overflow in `json_append_string()`. When we use `cjson.encoding()` to encode a string larger than 2GB, at specific compilation flags, an integer overflow may occur leading to truncation, resulting in the part of the string larger than 2GB not being encoded. On the other hand, this overflow doesn't cause any read or write out-of-range or segment fault. 1) using -O0 for lua_cjson (`make LUA_DEBUG=yes`) In this case, `i` will overflow and leads to truncation. When `i` reaches `INT_MAX+1` and overflows to INT_MIN, when compared to len, `i` (1000000..00) is expanded to 64 bits signed integer (1111111.....000000) . At this point i will be greater than len and jump out of the loop, so `for (i = 0; i < len; i++)` will loop up to 2^31 times, and the part of larger than 2GB will be truncated. ```asm `i` => -0x24(%rbp) <+253>: addl $0x1,-0x24(%rbp) ; overflow if i large than 2^31 <+257>: mov -0x24(%rbp),%eax <+260>: movslq %eax,%rdx ; move a 32-bit value with sign extension into a 64-bit signed <+263>: mov -0x20(%rbp),%rax <+267>: cmp %rax,%rdx ; check `i < len` <+270>: jb 0x212600 <json_append_string+148> ``` 2) using -O2/-O3 for lua_cjson (`make LUA_DEBUG=no`, **the default**) In this case, because singed integer overflow is an undefined behavior, `i` will not overflow. `i` will be optimized by the compiler and use 64-bit registers for all subsequent instructions. ```asm <+180>: add $0x1,%rbx ; Using 64-bit register `rbx` for i++ <+184>: lea 0x1(%rdx),%rsi <+188>: mov %rsi,0x10(%rbp) <+192>: mov %al,(%rcx,%rdx,1) <+195>: cmp %rbx,(%rsp) ; check `i < len` <+199>: ja 0x20b63a <json_append_string+154> ``` 3) using 32bit Because `strbuf_ensure_empty_length()` preallocates memory of length (len * 6 + 2), in 32-bit `cjson.encode()` can only handle strings smaller than ((2 ^ 32) - 3 ) / 6. So 32bit is not affected. Also change `i` in `strbuf_append_string()` to `size_t`. Since its second argument `str` is taken from the `char2escape` string array which is never larger than 6, so `strbuf_append_string()` is not at risk of overflow (the bug was unreachable).
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- 10 Jul, 2023 1 commit
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Oran Agra authored
* Fix integer overflows due to using wrong integer size. * Add assertions / panic when overflow still happens. * Deletion of dead code to avoid need to maintain it * Some changes are not because of bugs, but rather paranoia. * Improve cmsgpack and cjson test coverage. Co-authored-by:
Yossi Gottlieb <yossigo@gmail.com>
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- 16 Mar, 2023 1 commit
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Meir Shpilraien (Spielrein) authored
Allow running blocking commands from within a module using `RM_Call`. Today, when `RM_Call` is used, the fake client that is used to run command is marked with `CLIENT_DENY_BLOCKING` flag. This flag tells the command that it is not allowed to block the client and in case it needs to block, it must fallback to some alternative (either return error or perform some default behavior). For example, `BLPOP` fallback to simple `LPOP` if it is not allowed to block. All the commands must respect the `CLIENT_DENY_BLOCKING` flag (including module commands). When the command invocation finished, Redis asserts that the client was not blocked. This PR introduces the ability to call blocking command using `RM_Call` by passing a callback that will be called when the client will get unblocked. In order to do that, the user must explicitly say that he allow to perform blocking command by passing a new format specifier argument, `K`, to the `RM_Call` function. This new flag will tell Redis that it is allow to run blocking command and block the client. In case the command got blocked, Redis will return a new type of call reply (`REDISMODULE_REPLY_PROMISE`). This call reply indicates that the command got blocked and the user can set the on_unblocked handler using `RM_CallReplyPromiseSetUnblockHandler`. When clients gets unblocked, it eventually reaches `processUnblockedClients` function. This is where we check if the client is a fake module client and if it is, we call the unblock callback instead of performing the usual unblock operations. **Notice**: `RM_CallReplyPromiseSetUnblockHandler` must be called atomically along side the command invocation (without releasing the Redis lock in between). In addition, unlike other CallReply types, the promise call reply must be released by the module when the Redis GIL is acquired. The module can abort the execution on the blocking command (if it was not yet executed) using `RM_CallReplyPromiseAbort`. the API will return `REDISMODULE_OK` on success and `REDISMODULE_ERR` if the operation is already executed. **Notice** that in case of misbehave module, Abort might finished successfully but the operation will not really be aborted. This can only happened if the module do not respect the disconnect callback of the blocked client. For pure Redis commands this can not happened. ### Atomicity Guarantees The API promise that the unblock handler will run atomically as an execution unit. This means that all the operation performed on the unblock handler will be wrapped with a multi exec transaction when replicated to the replica and AOF. The API **do not** grantee any other atomicity properties such as when the unblock handler will be called. This gives us the flexibility to strengthen the grantees (or not) in the future if we will decide that we need a better guarantees. That said, the implementation **does** provide a better guarantees when performing pure Redis blocking command like `BLPOP`. In this case the unblock handler will run atomically with the operation that got unblocked (for example, in case of `BLPOP`, the unblock handler will run atomically with the `LPOP` operation that run when the command got unblocked). This is an implementation detail that might be change in the future and the module writer should not count on that. ### Calling blocking commands while running on script mode (`S`) `RM_Call` script mode (`S`) was introduced on #0372. It is used for usecases where the command that was invoked on `RM_Call` comes from a user input and we want to make sure the user will not run dangerous commands like `shutdown`. Some command, such as `BLPOP`, are marked with `NO_SCRIPT` flag, which means they will not be allowed on script mode. Those commands are marked with `NO_SCRIPT` just because they are blocking commands and not because they are dangerous. Now that we can run blocking commands on RM_Call, there is no real reason not to allow such commands on script mode. The underline problem is that the `NO_SCRIPT` flag is abused to also mark some of the blocking commands (notice that those commands know not to block the client if it is not allowed to do so, and have a fallback logic to such cases. So even if those commands were not marked with `NO_SCRIPT` flag, it would not harm Redis, and today we can already run those commands within multi exec). In addition, not all blocking commands are marked with `NO_SCRIPT` flag, for example `blmpop` are not marked and can run from within a script. Those facts shows that there are some ambiguity about the meaning of the `NO_SCRIPT` flag, and its not fully clear where it should be use. The PR suggest that blocking commands should not be marked with `NO_SCRIPT` flag, those commands should handle `CLIENT_DENY_BLOCKING` flag and only block when it's safe (like they already does today). To achieve that, the PR removes the `NO_SCRIPT` flag from the following commands: * `blmove` * `blpop` * `brpop` * `brpoplpush` * `bzpopmax` * `bzpopmin` * `wait` This might be considered a breaking change as now, on scripts, instead of getting `command is not allowed from script` error, the user will get some fallback behavior base on the command implementation. That said, the change matches the behavior of scripts and multi exec with respect to those commands and allow running them on `RM_Call` even when script mode is used. ### Additional RedisModule API and changes * `RM_BlockClientSetPrivateData` - Set private data on the blocked client without the need to unblock the client. This allows up to set the promise CallReply as the private data of the blocked client and abort it if the client gets disconnected. * `RM_BlockClientGetPrivateData` - Return the current private data set on a blocked client. We need it so we will have access to this private data on the disconnect callback. * On RM_Call, the returned reply will be added to the auto memory context only if auto memory is enabled, this allows us to keep the call reply for longer time then the context lifetime and does not force an unneeded borrow relationship between the CallReply and the RedisModuleContext.
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- 11 Mar, 2023 1 commit
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guybe7 authored
Work in progress towards implementing a reply schema as part of COMMAND DOCS, see #9845 Since ironing the details of the reply schema of each and every command can take a long time, we would like to merge this PR when the infrastructure is ready, and let this mature in the unstable branch. Meanwhile the changes of this PR are internal, they are part of the repo, but do not affect the produced build. ### Background In #9656 we add a lot of information about Redis commands, but we are missing information about the replies ### Motivation 1. Documentation. This is the primary goal. 2. It should be possible, based on the output of COMMAND, to be able to generate client code in typed languages. In order to do that, we need Redis to tell us, in detail, what each reply looks like. 3. We would like to build a fuzzer that verifies the reply structure (for now we use the existing testsuite, see the "Testing" section) ### Schema The idea is to supply some sort of schema for the various replies of each command. The schema will describe the conceptual structure of the reply (for generated clients), as defined in RESP3. Note that the reply structure itself may change, depending on the arguments (e.g. `XINFO STREAM`, with and without the `FULL` modifier) We decided to use the standard json-schema (see https://json-schema.org/) as the reply-schema. Example for `BZPOPMIN`: ``` "reply_schema": { "oneOf": [ { "description": "Timeout reached and no elements were popped.", "type": "null" }, { "description": "The keyname, popped member, and its score.", "type": "array", "minItems": 3, "maxItems": 3, "items": [ { "description": "Keyname", "type": "string" }, { "description": "Member", "type": "string" }, { "description": "Score", "type": "number" } ] } ] } ``` #### Notes 1. It is ok that some commands' reply structure depends on the arguments and it's the caller's responsibility to know which is the relevant one. this comes after looking at other request-reply systems like OpenAPI, where the reply schema can also be oneOf and the caller is responsible to know which schema is the relevant one. 2. The reply schemas will describe RESP3 replies only. even though RESP3 is structured, we want to use reply schema for documentation (and possibly to create a fuzzer that validates the replies) 3. For documentation, the description field will include an explanation of the scenario in which the reply is sent, including any relation to arguments. for example, for `ZRANGE`'s two schemas we will need to state that one is with `WITHSCORES` and the other is without. 4. For documentation, there will be another optional field "notes" in which we will add a short description of the representation in RESP2, in case it's not trivial (RESP3's `ZRANGE`'s nested array vs. RESP2's flat array, for example) Given the above: 1. We can generate the "return" section of all commands in [redis-doc](https://redis.io/commands/) (given that "description" and "notes" are comprehensive enough) 2. We can generate a client in a strongly typed language (but the return type could be a conceptual `union` and the caller needs to know which schema is relevant). see the section below for RESP2 support. 3. We can create a fuzzer for RESP3. ### Limitations (because we are using the standard json-schema) The problem is that Redis' replies are more diverse than what the json format allows. This means that, when we convert the reply to a json (in order to validate the schema against it), we lose information (see the "Testing" section below). The other option would have been to extend the standard json-schema (and json format) to include stuff like sets, bulk-strings, error-string, etc. but that would mean also extending the schema-validator - and that seemed like too much work, so we decided to compromise. Examples: 1. We cannot tell the difference between an "array" and a "set" 2. We cannot tell the difference between simple-string and bulk-string 3. we cannot verify true uniqueness of items in commands like ZRANGE: json-schema doesn't cover the case of two identical members with different scores (e.g. `[["m1",6],["m1",7]]`) because `uniqueItems` compares (member,score) tuples and not just the member name. ### Testing This commit includes some changes inside Redis in order to verify the schemas (existing and future ones) are indeed correct (i.e. describe the actual response of Redis). To do that, we added a debugging feature to Redis that causes it to produce a log of all the commands it executed and their replies. For that, Redis needs to be compiled with `-DLOG_REQ_RES` and run with `--reg-res-logfile <file> --client-default-resp 3` (the testsuite already does that if you run it with `--log-req-res --force-resp3`) You should run the testsuite with the above args (and `--dont-clean`) in order to make Redis generate `.reqres` files (same dir as the `stdout` files) which contain request-response pairs. These files are later on processed by `./utils/req-res-log-validator.py` which does: 1. Goes over req-res files, generated by redis-servers, spawned by the testsuite (see logreqres.c) 2. For each request-response pair, it validates the response against the request's reply_schema (obtained from the extended COMMAND DOCS) 5. In order to get good coverage of the Redis commands, and all their different replies, we chose to use the existing redis test suite, rather than attempt to write a fuzzer. #### Notes about RESP2 1. We will not be able to use the testing tool to verify RESP2 replies (we are ok with that, it's time to accept RESP3 as the future RESP) 2. Since the majority of the test suite is using RESP2, and we want the server to reply with RESP3 so that we can validate it, we will need to know how to convert the actual reply to the one expected. - number and boolean are always strings in RESP2 so the conversion is easy - objects (maps) are always a flat array in RESP2 - others (nested array in RESP3's `ZRANGE` and others) will need some special per-command handling (so the client will not be totally auto-generated) Example for ZRANGE: ``` "reply_schema": { "anyOf": [ { "description": "A list of member elements", "type": "array", "uniqueItems": true, "items": { "type": "string" } }, { "description": "Members and their scores. Returned in case `WITHSCORES` was used.", "notes": "In RESP2 this is returned as a flat array", "type": "array", "uniqueItems": true, "items": { "type": "array", "minItems": 2, "maxItems": 2, "items": [ { "description": "Member", "type": "string" }, { "description": "Score", "type": "number" } ] } } ] } ``` ### Other changes 1. Some tests that behave differently depending on the RESP are now being tested for both RESP, regardless of the special log-req-res mode ("Pub/Sub PING" for example) 2. Update the history field of CLIENT LIST 3. Added basic tests for commands that were not covered at all by the testsuite ### TODO - [x] (maybe a different PR) add a "condition" field to anyOf/oneOf schemas that refers to args. e.g. when `SET` return NULL, the condition is `arguments.get||arguments.condition`, for `OK` the condition is `!arguments.get`, and for `string` the condition is `arguments.get` - https://github.com/redis/redis/issues/11896 - [x] (maybe a different PR) also run `runtest-cluster` in the req-res logging mode - [x] add the new tests to GH actions (i.e. compile with `-DLOG_REQ_RES`, run the tests, and run the validator) - [x] (maybe a different PR) figure out a way to warn about (sub)schemas that are uncovered by the output of the tests - https://github.com/redis/redis/issues/11897 - [x] (probably a separate PR) add all missing schemas - [x] check why "SDOWN is triggered by misconfigured instance replying with errors" fails with --log-req-res - [x] move the response transformers to their own file (run both regular, cluster, and sentinel tests - need to fight with the tcl including mechanism a bit) - [x] issue: module API - https://github.com/redis/redis/issues/11898 - [x] (probably a separate PR): improve schemas: add `required` to `object`s - https://github.com/redis/redis/issues/11899 Co-authored-by:
Ozan Tezcan <ozantezcan@gmail.com> Co-authored-by:
Hanna Fadida <hanna.fadida@redislabs.com> Co-authored-by:
Oran Agra <oran@redislabs.com> Co-authored-by:
Shaya Potter <shaya@redislabs.com>
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- 28 Feb, 2023 1 commit
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uriyage authored
As `sdsRemoveFreeSpace` have an impact on performance even if it is a no-op (see details at #11508). Only call the function when there is a possibility that the string contains free space. * For strings coming from the network, it's only if they're bigger than PROTO_MBULK_BIG_ARG * For strings coming from scripts, it's only if they're smaller than LUA_CMD_OBJCACHE_MAX_LEN * For strings coming from modules, it could be anything. Co-authored-by:
Oran Agra <oran@redislabs.com> Co-authored-by:
sundb <sundbcn@gmail.com>
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- 04 Jan, 2023 1 commit
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Oran Agra authored
TLDR: solve a problem introduced in Redis 7.0.6 (#11541) with RM_CommandFilterArgInsert being called from scripts, which can lead to memory corruption. Libc realloc can return the same pointer even if the size was changed. The code in freeLuaRedisArgv had an assumption that if the pointer didn't change, then the allocation didn't change, and the cache can still be reused. However, if rewriteClientCommandArgument or RM_CommandFilterArgInsert were used, it could be that we realloced the argv array, and the pointer didn't change, then a consecutive command being executed from Lua can use that argv cache reaching beyond its size. This was actually only possible with modules, since the decision to realloc was based on argc, rather than argv_len.
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- 05 Dec, 2022 1 commit
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filipe oliveira authored
This mechanism aims to reduce calls to malloc and free when preparing the arguments the script sends to redis commands. This is a mechanism was originally implemented in 48c49c48 and 4f686555 , and was removed in #10220 (thinking it's not needed and that it has no impact), but it now turns out it was wrong, and it indeed provides some 5% performance improvement. The implementation is a little bit too simplistic, it assumes consecutive calls use the same size in the same arg index, but that's arguably sufficient since it's only aimed at caching very small things. We could even consider always pre-allocating args to the full LUA_CMD_OBJCACHE_MAX_LEN (64 bytes) rather than the right size for the argument, that would increase the chance they'll be able to be re-used. But in some way this is already happening since we're using sdsalloc, which in turn uses s_malloc_usable and takes ownership of the full side of the allocation, so we are padded to the allocator bucket size. Co-authored-by:
Oran Agra <oran@redislabs.com> Co-authored-by:
sundb <sundbcn@gmail.com>
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- 09 Oct, 2022 1 commit
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Binbin authored
Freeze time during execution of scripts and all other commands. This means that a key is either expired or not, and doesn't change state during a script execution. resolves #10182 This PR try to add a new `commandTimeSnapshot` function. The function logic is extracted from `keyIsExpired`, but the related calls to `fixed_time_expire` and `mstime()` are removed, see below. In commands, we will avoid calling `mstime()` multiple times and just use the one that sampled in call. The background is, e.g. using `PEXPIRE 1` with valgrind sometimes result in the key being deleted rather than expired. The reason is that both `PEXPIRE` command and `checkAlreadyExpired` call `mstime()` separately. There are other more important changes in this PR: 1. Eliminate `fixed_time_expire`, it is no longer needed. When we want to sample time we should always use a time snapshot. We will use `in_nested_call` instead to update the cached time in `call`. 2. Move the call for `updateCachedTime` from `serverCron` to `afterSleep`. Now `commandTimeSnapshot` will always return the sample time, the `lookupKeyReadWithFlags` call in `getNodeByQuery` will get a outdated cached time (because `processCommand` is out of the `call` context). We put the call to `updateCachedTime` in `aftersleep`. 3. Cache the time each time the module lock Redis. Call `updateCachedTime` in `moduleGILAfterLock`, affecting `RM_ThreadSafeContextLock` and `RM_ThreadSafeContextTryLock` Currently the commandTimeSnapshot change affects the following TTL commands: - SET EX / SET PX - EXPIRE / PEXPIRE - SETEX / PSETEX - GETEX EX / GETEX PX - TTL / PTTL - EXPIRETIME / PEXPIRETIME - RESTORE key TTL And other commands just use the cached mstime (including TIME). This is considered to be a breaking change since it can break a script that uses a loop to wait for a key to expire.
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- 16 Aug, 2022 1 commit
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Valentino Geron authored
Make sure the script calls in the tests declare the keys they intend to use. Do that with minimal changes to existing lines (so many scripts still have a hard coded key names) Co-authored-by:
Valentino Geron <valentino@redis.com>
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- 07 Aug, 2022 1 commit
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Valentino Geron authored
some skip tags were missing on some tests avoid using HELLO if denytags has resp3 (target server may not support it) Co-authored-by:
Valentino Geron <valentino@redis.com>
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- 26 Jul, 2022 1 commit
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Meir Shpilraien (Spielrein) authored
Fix #11030, use lua_rawget to avoid triggering metatables. #11030 shows how return `_G` from the Lua script (either function or eval), cause the Lua interpreter to Panic and the Redis processes to exit with error code 1. Though return `_G` only panic on Redis 7 and 6.2.7, the underline issue exists on older versions as well (6.0 and 6.2). The underline issue is returning a table with a metatable such that the metatable raises an error. The following example demonstrate the issue: ``` 127.0.0.1:6379> eval "local a = {}; setmetatable(a,{__index=function() foo() end}) return a" 0 Error: Server closed the connection ``` ``` PANIC: unprotected error in call to Lua API (user_script:1: Script attempted to access nonexistent global variable 'foo') ``` The Lua panic happened because when returning the result to the client, Redis needs to introspect the returning table and transform the table into a resp. In order to scan the table, Redis uses `lua_gettable` api which might trigger the metatable (if exists) and might raise an error. This code is not running inside `pcall` (Lua protected call), so raising an error causes the Lua to panic and exit. Notice that this is not a crash, its a Lua panic that exit with error code 1. Returning `_G` panics on Redis 7 and 6.2.7 because on those versions `_G` has a metatable that raises error when trying to fetch a none existing key. ### Solution Instead of using `lua_gettable` that might raise error and cause the issue, use `lua_rawget` that simply return the value from the table without triggering any metatable logic. This is promised not to raise and error. The downside of this solution is that it might be considered as breaking change, if someone rely on metatable in the returned value. An alternative solution is to wrap this entire logic with `pcall` (Lua protected call), this alternative require a much bigger refactoring. ### Back Porting The same fix will work on older versions as well (6.2, 6.0). Notice that on those version, the issue can cause Redis to crash if inside the metatable logic there is an attempt to accesses Redis (`redis.call`). On 7.0, there is not crash and the `redis.call` is executed as if it was done from inside the script itself. ### Tests Tests was added the verify the fix
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- 14 Jun, 2022 2 commits
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Oran Agra authored
If a script made a modification and then was interrupted for taking too long. there's a chance redis will detect that a replica dropped and would like to reject write commands with NOREPLICAS due to insufficient good replicas. returning an error on a command in this case breaks the script atomicity. The same could in theory happen with READONLY, MISCONF, but i don't think these state changes can happen during script execution.
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Oran Agra authored
I noticed that scripting.tcl uses INFO from within a script and thought it's an overkill and concluded it's nicer to use another CMD_STALE command, decided to use ECHO, and then noticed it's not at all allowed in stale mode. probably overlooked at #6843
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- 01 Jun, 2022 2 commits
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Oran Agra authored
The important part is that read-only scripts (not just EVAL_RO and FCALL_RO, but also ones with `no-writes` executed by normal EVAL or FCALL), will now be permitted to run during CLIENT PAUSE WRITE (unlike before where only the _RO commands would be processed). Other than that, some errors like OOM, READONLY, MASTERDOWN are now handled by processCommand, rather than the command itself affects the error string (and even error code in some cases), and command stats. Besides that, now the `may-replicate` commands, PFCOUNT and PUBLISH, will be considered `write` commands in scripts and will be blocked in all read-only scripts just like other write commands. They'll also be blocked in EVAL_RO (i.e. even for scripts without the `no-writes` shebang flag. This commit also hides the `may_replicate` flag from the COMMAND command output. this is a **breaking change**. background about may_replicate: We don't want to expose a no...
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Oran Agra authored
Fix broken protocol in MISCONF error, RM_Yield bugs, RM_Call(EVAL) OOM check bug, and new RM_Call checks. (#10786) * Fix broken protocol when redis can't persist to RDB (general commands, not modules), excessive newline. regression of #10372 (7.0 RC3) * Fix broken protocol when Redis can't persist to AOF (modules and scripts), missing newline. * Fix bug in OOM check of EVAL scripts called from RM_Call. set the cached OOM state for scripts before executing module commands too, so that it can serve scripts that are executed by modules. i.e. in the past EVAL executed by RM_Call could have either falsely fail or falsely succeeded because of a wrong cached OOM state flag. * Fix bugs with RM_Yield: 1. SHUTDOWN should only accept the NOSAVE mode 2. Avoid eviction during yield command processing. 3. Avoid processing master client commands while yielding from another client * Add new two more checks to RM_Call script mode. 1. READONLY You can't write against a read only replica 2. MASTERDOWN Link with MASTER is down and `replica-serve-stale-data` is set to `no` * Add new RM_Call flag to let redis automatically refuse `deny-oom` commands while over the memory limit. * Add tests to cover various errors from Scripts, Modules, Modules calling scripts, and Modules calling commands in script mode. Add tests: * Looks like the MISCONF error was completely uncovered by the tests, add tests for it, including from scripts, and modules * Add tests for NOREPLICAS from scripts * Add tests for the various errors in module RM_Call, including RM_Call that calls EVAL, and RM_call in "eval mode". that includes: NOREPLICAS, READONLY, MASTERDOWN, MISCONF
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- 22 May, 2022 1 commit
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Oran Agra authored
Scripts that have the `no-writes` flag, cannot execute write commands, and since all `deny-oom` commands are write commands, we now act as if the `allow-oom` flag is implicitly set for scripts that set the `no-writes` flag. this also implicitly means that the EVAL*_RO and FCALL_RO commands can never fails with OOM error. Note about a bug that's no longer relevant: There was an issue with EVAL*_RO using shebang not being blocked correctly in OOM state: When an EVAL script declares a shebang, it was by default not allowed to run in OOM state. but this depends on a flag that is updated before the command is executed, which was not updated in case of the `_RO` variants. the result is that if the previous cached state was outdated (either true or false), the script will either unjustly fail with OOM, or unjustly allowed to run despite the OOM state. It doesn't affect scripts without a shebang since these depend on the actual commands they run, and since these are only read commands, they don't care for that cached oom state flag. it did affect scripts with shebang and no allow-oom flag, bug after the change in this PR, scripts that are run with eval_ro would implicitly have that flag so again the cached state doesn't matter. p.s. this isn't a breaking change since all it does is allow scripts to run when they should / could rather than blocking them.
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- 26 Apr, 2022 2 commits
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meir authored
The white list is done by setting a metatable on the global table before initializing any library. The metatable set the `__newindex` field to a function that check the white list before adding the field to the table. Fields which is not on the white list are simply ignored. After initialization phase is done we protect the global table and each table that might be reachable from the global table. For each table we also protect the table metatable if exists.
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meir authored
Use the new `lua_enablereadonlytable` Lua API to protect the global tables of both evals scripts and functions. For eval scripts, the implemetation is easy, We simply call `lua_enablereadonlytable` on the global table to turn it into a readonly table. On functions its more complecated, we want to be able to switch globals between load run and function run. To achieve this, we create a new empty table that acts as the globals table for function, we control the actual globals using metatable manipulation. Notice that even if the user gets a pointer to the original tables, all the tables are set to be readonly (using `lua_enablereadonlytable` Lua API) so he can not change them. The following inlustration better explain the solution: ``` Global table {} <- global table metatable {.__index = __real_globals__} ``` The `__real_globals__` is set depends on the run context (function load or function call). Why this solution is needed and its not enough to simply switch globals? When we run in the context of function load and create our functions, our function gets the current globals that was set when they were created. Replacing the globals after the creation will not effect them. This is why this trick it mandatory.
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- 19 Apr, 2022 1 commit
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Oran Agra authored
some skip tags where missing on some tests....
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- 17 Apr, 2022 1 commit
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Meir Shpilraien (Spielrein) authored
The tests verify that loading a binary payload to the Lua interpreter raises an error. The Lua code modification was done here: fdf9d455 which force the Lau interpreter to always use the text parser.
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- 14 Apr, 2022 1 commit
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Madelyn Olson authored
By the convention of errors, there is supposed to be a space between the code and the name. While looking at some lua stuff I noticed that interpreter errors were not adding the space, so some clients will try to map the detailed error message into the error. We have tests that hit this condition, but they were just checking that the string "starts" with ERR. I updated some other tests with similar incorrect string checking. This isn't complete though, as there are other ways we check for ERR I didn't fix. Produces some fun output like: ``` # Errorstats errorstat_ERR:count=1 errorstat_ERRuser_script_1_:count=1 ```
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- 05 Apr, 2022 1 commit
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Meir Shpilraien (Spielrein) authored
## Move library meta data to be part of the library payload. Following the discussion on https://github.com/redis/redis/issues/10429 and the intention to add (in the future) library versioning support, we believe that the entire library metadata (like name and engine) should be part of the library payload and not provided by the `FUNCTION LOAD` command. The reasoning behind this is that the programmer who developed the library should be the one who set those values (name, engine, and in the future also version). **It is not the responsibility of the admin who load the library into the database.** The PR moves all the library metadata (engine and function name) to be part of the library payload. The metadata needs to be provided on the first line of the payload using the shebang format (`#!<engine> name=<name>`), example: ```lua #!lua name=test redis.register_function('foo', function() return 1 end) ``` The above script will run on the Lua engine and will create a library called `test`. ## API Changes (compare to 7.0 rc2) * `FUNCTION LOAD` command was change and now it simply gets the library payload and extract the engine and name from the payload. In addition, the command will now return the function name which can later be used on `FUNCTION DELETE` and `FUNCTION LIST`. * The description field was completely removed from`FUNCTION LOAD`, and `FUNCTION LIST` ## Breaking Changes (compare to 7.0 rc2) * Library description was removed (we can re-add it in the future either as part of the shebang line or an additional line). * Loading an AOF file that was generated by either 7.0 rc1 or 7.0 rc2 will fail because the old command syntax is invalid. ## Notes * Loading an RDB file that was generated by rc1 / rc2 **is** supported, Redis will automatically add the shebang to the libraries payloads (we can probably delete that code after 7.0.3 or so since there's no need to keep supporting upgrades from an RC build).
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- 04 Apr, 2022 1 commit
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Meir Shpilraien (Spielrein) authored
If, for some reason, Redis decides not to execute the script, we need to pop the function and error handler from Lua stack. Otherwise, eventually the Lua stack will explode. Relevant only for 7.0-rc1 and 7.0-rc2.
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- 27 Feb, 2022 1 commit
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Meir Shpilraien (Spielrein) authored
This PR fix 2 issues on Lua scripting: * Server error reply statistics (some errors were counted twice). * Error code and error strings returning from scripts (error code was missing / misplaced). ## Statistics a Lua script user is considered part of the user application, a sophisticated transaction, so we want to count an error even if handled silently by the script, but when it is propagated outwards from the script we don't wanna count it twice. on the other hand, if the script decides to throw an error on its own (using `redis.error_reply`), we wanna count that too. Besides, we do count the `calls` in command statistics for the commands the script calls, we we should certainly also count `failed_calls`. So when a simple `eval "return redis.call('set','x','y')" 0` fails, it should count the failed call to both SET and EVAL, but the `errorstats` and `total_error_replies` should be counted only once. The PR changes the error object that is raised on errors. Instead of raising a simple Lua string, Redis will raise a Lua table in the following format: ``` { err='<error message (including error code)>', source='<User source file name>', line='<line where the error happned>', ignore_error_stats_update=true/false, } ``` The `luaPushError` function was modified to construct the new error table as describe above. The `luaRaiseError` was renamed to `luaError` and is now simply called `lua_error` to raise the table on the top of the Lua stack as the error object. The reason is that since its functionality is changed, in case some Redis branch / fork uses it, it's better to have a compilation error than a bug. The `source` and `line` fields are enriched by the error handler (if possible) and the `ignore_error_stats_update` is optional and if its not present then the default value is `false`. If `ignore_error_stats_update` is true, the error will not be counted on the error stats. When parsing Redis call reply, each error is translated to a Lua table on the format describe above and the `ignore_error_stats_update` field is set to `true` so we will not count errors twice (we counted this error when we invoke the command). The changes in this PR might have been considered as a breaking change for users that used Lua `pcall` function. Before, the error was a string and now its a table. To keep backward comparability the PR override the `pcall` implementation and extract the error message from the error table and return it. Example of the error stats update: ``` 127.0.0.1:6379> lpush l 1 (integer) 2 127.0.0.1:6379> eval "return redis.call('get', 'l')" 0 (error) WRONGTYPE Operation against a key holding the wrong kind of value. script: e471b73f1ef44774987ab00bdf51f21fd9f7974a, on @user_script:1. 127.0.0.1:6379> info Errorstats # Errorstats errorstat_WRONGTYPE:count=1 127.0.0.1:6379> info commandstats # Commandstats cmdstat_eval:calls=1,usec=341,usec_per_call=341.00,rejected_calls=0,failed_calls=1 cmdstat_info:calls=1,usec=35,usec_per_call=35.00,rejected_calls=0,failed_calls=0 cmdstat_lpush:calls=1,usec=14,usec_per_call=14.00,rejected_calls=0,failed_calls=0 cmdstat_get:calls=1,usec=10,usec_per_call=10.00,rejected_calls=0,failed_calls=1 ``` ## error message We can now construct the error message (sent as a reply to the user) from the error table, so this solves issues where the error message was malformed and the error code appeared in the middle of the error message: ```diff 127.0.0.1:6379> eval "return redis.call('set','x','y')" 0 -(error) ERR Error running script (call to 71e6319f97b0fe8bdfa1c5df3ce4489946dda479): @user_script:1: OOM command not allowed when used memory > 'maxmemory'. +(error) OOM command not allowed when used memory > 'maxmemory' @user_script:1. Error running script (call to 71e6319f97b0fe8bdfa1c5df3ce4489946dda479) ``` ```diff 127.0.0.1:6379> eval "redis.call('get', 'l')" 0 -(error) ERR Error running script (call to f_8a705cfb9fb09515bfe57ca2bd84a5caee2cbbd1): @user_script:1: WRONGTYPE Operation against a key holding the wrong kind of value +(error) WRONGTYPE Operation against a key holding the wrong kind of value script: 8a705cfb9fb09515bfe57ca2bd84a5caee2cbbd1, on @user_script:1. ``` Notica that `redis.pcall` was not change: ``` 127.0.0.1:6379> eval "return redis.pcall('get', 'l')" 0 (error) WRONGTYPE Operation against a key holding the wrong kind of value ``` ## other notes Notice that Some commands (like GEOADD) changes the cmd variable on the client stats so we can not count on it to update the command stats. In order to be able to update those stats correctly we needed to promote `realcmd` variable to be located on the client struct. Tests was added and modified to verify the changes. Related PR's: #10279, #10218, #10278, #10309 Co-authored-by:
Oran Agra <oran@redislabs.com>
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- 08 Feb, 2022 1 commit
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yoav-steinberg authored
This PR handles inconsistencies in errors returned from lua scripts. Details of the problem can be found in #10165. ### Changes - Remove double stack trace. It's enough that a stack trace is automatically added by the engine's error handler see https://github.com/redis/redis/blob/d0bc4fff18afdf9e5421cc88e23ffbb876ecaec3/src/function_lua.c#L472-L485 and https://github.com/redis/redis/blob/d0bc4fff18afdf9e5421cc88e23ffbb876ecaec3/src/eval.c#L243-L255 - Make sure all errors a preceded with an error code. Passing a simple string to `luaPushError()` will prepend it with a generic `ERR` error code. - Make sure lua error table doesn't include a RESP `-` error status. Lua stores redis error's as a lua table with a single `err` field and a string. When the string is translated back to RESP we add a `-` to it. See https://github.com/redis/redis/blob/d0bc4fff18afdf9e5421cc88e23ffbb876ecaec3/src/script_lua.c#L510-L517 So there's no need to store it in the lua table. ### Before & After ```diff --- <unnamed> +++ <unnamed> @@ -1,14 +1,14 @@ 1: config set maxmemory 1 2: +OK 3: eval "return redis.call('set','x','y')" 0 - 4: -ERR Error running script (call to 71e6319f97b0fe8bdfa1c5df3ce4489946dda479): @user_script:1: @user_script: 1: -OOM command not allowed when used memory > 'maxmemory'. + 4: -ERR Error running script (call to 71e6319f97b0fe8bdfa1c5df3ce4489946dda479): @user_script:1: OOM command not allowed when used memory > 'maxmemory'. 5: eval "return redis.pcall('set','x','y')" 0 - 6: -@user_script: 1: -OOM command not allowed when used memory > 'maxmemory'. + 6: -OOM command not allowed when used memory > 'maxmemory'. 7: eval "return redis.call('select',99)" 0 8: -ERR Error running script (call to 4ad5abfc50bbccb484223905f9a16f09cd043ba8): @user_script:1: ERR DB index is out of range 9: eval "return redis.pcall('select',99)" 0 10: -ERR DB index is out of range 11: eval_ro "return redis.call('set','x','y')" 0 -12: -ERR Error running script (call to 71e6319f97b0fe8bdfa1c5df3ce4489946dda479): @user_script:1: @user_script: 1: Write commands are not allowed from read-only scripts. +12: -ERR Error running script (call to 71e6319f97b0fe8bdfa1c5df3ce4489946dda479): @user_script:1: ERR Write commands are not allowed from read-only scripts. 13: eval_ro "return redis.pcall('set','x','y')" 0 -14: -@user_script: 1: Write commands are not allowed from read-only scripts. +14: -ERR Write commands are not allowed from read-only scripts. ```
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- 07 Feb, 2022 1 commit
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yoav-steinberg authored
Changes: 1. Adds the `redis.acl_check_cmd()` api to lua scripts. It can be used to check if the current user has permissions to execute a given command. The new function receives the command to check as an argument exactly like `redis.call()` receives the command to execute as an argument. 2. In the PR I unified the code used to convert lua arguments to redis argv arguments from both the new `redis.acl_check_cmd()` API and the `redis.[p]call()` API. This cleans up potential duplicate code. 3. While doing the refactoring in 2 I noticed there's an optimization to reduce allocation calls when parsing lua arguments into an `argv` array in the `redis.[p]call()` implementation. These optimizations were introduced years ago in 48c49c48 and 4f686555. It is unclear why this was added. The original commit message claims a 4% performance increase which I couldn't recreate and might not be worth it even if it did recreate. This PR removes that optimization. Following are details of the benchmark I did that couldn't reveal any performance improvements due to this optimization: ``` benchmark 1: src/redis-benchmark -P 500 -n 10000000 eval 'return redis.call("ping")' 0 benchmark 2: src/redis-benchmark -P 500 -r 1000 -n 1000000 eval 'return redis.call("mset","k1__rand_int__","v1__rand_int__","k2__rand_int__","v2__rand_int__","k3__rand_int__","v3__rand_int__","k4__rand_int__","v4__rand_int__")' 0 benchmark 3: src/redis-benchmark -P 500 -r 1000 -n 100000 eval "for i=1,100,1 do redis.call('set','kk'..i,'vv'..__rand_int__) end return redis.call('get','kk5')" 0 benchmark 4: src/redis-benchmark -P 500 -r 1000 -n 1000000 eval 'return redis.call("mset","k1__rand_int__","v1__rand_int__","k2__rand_int__","v2__rand_int__","k3__rand_int__","v3__rand_int__","k4__rand_int__","v4__rand_int__xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx")' ``` I ran the benchmark on this branch with and without commit 68b71680a4d3bb8f0509e06578a9f15d05b92a47 Results in requests per second: cmd | without optimization | without optimization 2nd run | with original optimization | with original optimization 2nd run -- | -- | -- | -- | -- 1 | 461233.34 | 477395.31 | 471098.16 | 469946.91 2 | 34774.14 | 35469.8 | 35149.38 | 34464.93 3 | 6390.59 | 6281.41 | 6146.28 | 6464.12 4 | 28005.71 | | 27965.77 | As you can see, different use cases showed identical or negligible performance differences. So finally I decided to chuck the original optimization and simplify the code.
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- 25 Jan, 2022 1 commit
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Madelyn Olson authored
Correctly handle variable arity checks in scripts
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- 24 Jan, 2022 1 commit
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yoav-steinberg authored
In #10025 we added a mechanism for flagging certain properties for Redis Functions. This lead us to think we'd like to "port" this mechanism to Redis Scripts (`EVAL`) as well. One good reason for this, other than the added functionality is because it addresses the poor behavior we currently have in `EVAL` in case the script performs a (non DENY_OOM) write operation during OOM state. See #8478 (And a previous attempt to handle it via #10093) for details. Note that in Redis Functions **all** write operations (including DEL) will return an error during OOM state unless the function is flagged as `allow-oom` in which case no OOM checking is performed at all. This PR: - Enables setting `EVAL` (and `SCRIPT LOAD`) script flags as defined in #10025. - Provides a syntactical framework via [shebang](https://en.wikipedia.org/wiki/Shebang_(Unix)) for additional script annotations and even engine selection (instead of just lua) for scripts. - Provides backwards compatibility so scripts without the new annotations will behave as they did before. - Appropriate tests. - Changes `EVAL[SHA]/_RO` to be flagged as `STALE` commands. This makes it possible to flag individual scripts as `allow-stale` or not flag them as such. In backwards compatibility mode these commands will return the `MASTERDOWN` error as before. - Changes `SCRIPT LOAD` to be flagged as a `STALE` command. This is mainly to make it logically compatible with the change to `EVAL` in the previous point. It enables loading a script on a stale server which is technically okay it doesn't relate directly to the server's dataset. Running the script does, but that won't work unless the script is explicitly marked as `allow-stale`. Note that even though the LUA syntax doesn't support hash tag comments `.lua` files do support a shebang tag on the top so they can be executed on Unix systems like any shell script. LUA's `luaL_loadfile` handles this as part of the LUA library. In the case of `luaL_loadbuffer`, which is what Redis uses, I needed to fix the input script in case of a shebang manually. I did this the same way `luaL_loadfile` does, by replacing the first line with a single line feed character.
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- 14 Jan, 2022 1 commit
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Meir Shpilraien (Spielrein) authored
# Redis Functions Flags Following the discussion on #10025 Added Functions Flags support. The PR is divided to 2 sections: * Add named argument support to `redis.register_function` API. * Add support for function flags ## `redis.register_function` named argument support The first part of the PR adds support for named argument on `redis.register_function`, example: ``` redis.register_function{ function_name='f1', callback=function() return 'hello' end, description='some desc' } ``` The positional arguments is also kept, which means that it still possible to write: ``` redis.register_function('f1', function() return 'hello' end) ``` But notice that it is no longer possible to pass the optional description argument on the positional argument version. Positional argument was change to allow passing only the mandatory arguments (function name and callback). To pass more arguments the user must use the named argument version. As with positional arguments, the `function_name` and `callback` is mandatory and an error will be raise if those are missing. Also, an error will be raise if an unknown argument name is given or the arguments type is wrong. Tests was added to verify the new syntax. ## Functions Flags The second part of the PR is adding functions flags support. Flags are given to Redis when the engine calls `functionLibCreateFunction`, supported flags are: * `no-writes` - indicating the function perform no writes which means that it is OK to run it on: * read-only replica * Using FCALL_RO * If disk error detected It will not be possible to run a function in those situations unless the function turns on the `no-writes` flag * `allow-oom` - indicate that its OK to run the function even if Redis is in OOM state, if the function will not turn on this flag it will not be possible to run it if OOM reached (even if the function declares `no-writes` and even if `fcall_ro` is used). If this flag is set, any command will be allow on OOM (even those that is marked with CMD_DENYOOM). The assumption is that this flag is for advance users that knows its meaning and understand what they are doing, and Redis trust them to not increase the memory usage. (e.g. it could be an INCR or a modification on an existing key, or a DEL command) * `allow-state` - indicate that its OK to run the function on stale replica, in this case we will also make sure the function is only perform `stale` commands and raise an error if not. * `no-cluster` - indicate to disallow running the function if cluster is enabled. Default behaviure of functions (if no flags is given): 1. Allow functions to read and write 2. Do not run functions on OOM 3. Do not run functions on stale replica 4. Allow functions on cluster ### Lua API for functions flags On Lua engine, it is possible to give functions flags as `flags` named argument: ``` redis.register_function{function_name='f1', callback=function() return 1 end, flags={'no-writes', 'allow-oom'}, description='description'} ``` The function flags argument must be a Lua table that contains all the requested flags, The following will result in an error: * Unknown flag * Wrong flag type Default behaviour is the same as if no flags are used. Tests were added to verify all flags functionality ## Additional changes * mark FCALL and FCALL_RO with CMD_STALE flag (unlike EVAL), so that they can run if the function was registered with the `allow-stale` flag. * Verify `CMD_STALE` on `scriptCall` (`redis.call`), so it will not be possible to call commands from script while stale unless the command is marked with the `CMD_STALE` flags. so that even if the function is allowed while stale we do not allow it to bypass the `CMD_STALE` flag of commands. * Flags section was added to `FUNCTION LIST` command to provide the set of flags for each function: ``` > FUNCTION list withcode 1) 1) "library_name" 2) "test" 3) "engine" 4) "LUA" 5) "description" 6) (nil) 7) "functions" 8) 1) 1) "name" 2) "f1" 3) "description" 4) (nil) 5) "flags" 6) (empty array) 9) "library_code" 10) "redis.register_function{function_name='f1', callback=function() return 1 end}" ``` * Added API to get Redis version from within a script, The redis version can be provided using: 1. `redis.REDIS_VERSION` - string representation of the redis version in the format of MAJOR.MINOR.PATH 2. `redis.REDIS_VERSION_NUM` - number representation of the redis version in the format of `0x00MMmmpp` (`MM` - major, `mm` - minor, `pp` - patch). The number version can be used to check if version is greater or less another version. The string version can be used to return to the user or print as logs. This new API is provided to eval scripts and functions, it also possible to use this API during functions loading phase.
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