- 08 Mar, 2023 26 commits
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Vitaly Arbuzov authored
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Vitaly Arbuzov authored
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Vitaly Arbuzov authored
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Vitaly Arbuzov authored
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Vitaly Arbuzov authored
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Vitaly Arbuzov authored
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Vitaly Arbuzov authored
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Vitaly Arbuzov authored
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Vitaly Arbuzov authored
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Vitaly Arbuzov authored
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Vitaly Arbuzov authored
Add assertion that command slot is correct after command execution, and make scripts that access multiple slots work correctly
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Vitaly Arbuzov authored
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Vitaly Arbuzov authored
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Vitaly Arbuzov authored
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Vitaly Arbuzov authored
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Vitaly Arbuzov authored
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Vitaly Arbuzov authored
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Vitaly Arbuzov authored
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Vitaly Arbuzov authored
Add comment Populate current dictionary in the right place
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Vitaly Arbuzov authored
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Vitaly Arbuzov authored
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Vitaly Arbuzov authored
* updated comments and formatting
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Vitaly Arbuzov authored
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Vitaly Arbuzov authored
Improve incremental rehashing by using a linked list instead of linear scan when finding rehash target
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Vitaly Arbuzov authored
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Vitaly Arbuzov authored
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- 23 Feb, 2023 1 commit
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Chen Tianjie authored
When no-touch mode is enabled, the client will not touch LRU/LFU of the keys it accesses, except when executing command `TOUCH`. This allows inspecting or modifying the key-space without affecting their eviction. Changes: - A command `CLIENT NO-TOUCH ON|OFF` to switch on and off this mode. - A client flag `#define CLIENT_NOTOUCH (1ULL<<45)`, which can be shown with `CLIENT INFO`, by the letter "T" in the "flags" field. - Clear `NO-TOUCH` flag in `clearClientConnectionState`, which is used by `RESET` command and resetting temp clients used by modules. - Also clear `NO-EVICT` flag in `clearClientConnectionState`, this might have been an oversight, spotted by @madolson. - A test using `DEBUG OBJECT` command to verify that LRU stat is not touched when no-touch mode is on. Co-authored-by:
chentianjie <chentianjie@alibaba-inc.com> Co-authored-by:
Madelyn Olson <34459052+madolson@users.noreply.github.com> Co-authored-by:
sundb <sundbcn@gmail.com>
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- 14 Feb, 2023 1 commit
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guybe7 authored
Starting from Redis 7.0 (#9890) we started wrapping everything a command propagates with MULTI/EXEC. The problem is that both SCAN and RANDOMKEY can lazy-expire arbitrary keys (similar behavior to active-expire), and put DELs in a transaction. Fix: When these commands are called without a parent exec-unit (e.g. not in EVAL or MULTI) we avoid wrapping their DELs in a transaction (for the same reasons active-expire and eviction avoids a transaction) This PR adds a per-command flag that indicates that the command may touch arbitrary keys (not the ones in the arguments), and uses that flag to avoid the MULTI-EXEC. For now, this flag is internal, since we're considering other solutions for the future. Note for cluster mode: if SCAN/RANDOMKEY is inside EVAL/MULTI it can still cause the same situation (as it always did), but it won't cause a CROSSSLOT because replicas and AOF do not perform slot checks. The problem with the above is mainly for 3rd party ecosystem tools that propagate commands from master to master, or feed an AOF file with redis-cli into a master. This PR aims to fix the regression in redis 7.0, and we opened #11792 to try to handle the bigger problem with lazy expire better for another release.
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- 12 Feb, 2023 1 commit
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Tian authored
# Background The RDB file is usually generated and used once and seldom used again, but the content would reside in page cache until OS evicts it. A potential problem is that once the free memory exhausts, the OS have to reclaim some memory from page cache or swap anonymous page out, which may result in a jitters to the Redis service. Supposing an exact scenario, a high-capacity machine hosts many redis instances, and we're upgrading the Redis together. The page cache in host machine increases as RDBs are generated. Once the free memory drop into low watermark(which is more likely to happen in older Linux kernel like 3.10, before [watermark_scale_factor](https://lore.kernel.org/lkml/1455813719-2395-1-git-send-email-hannes@cmpxchg.org/) is introduced, the `low watermark` is linear to `min watermark`, and there'is not too much buffer space for `kswapd` to be wake up to reclaim memory), a `direct reclaim` happens, which means the process would stall to wait for memory allocation. # What the PR does The PR introduces a capability to reclaim the cache when the RDB is operated. Generally there're two cases, read and write the RDB. For read it's a little messy to address the incremental reclaim, so the reclaim is done in one go in background after the load is finished to avoid blocking the work thread. For write, incremental reclaim amortizes the work of reclaim so no need to put it into background, and the peak watermark of cache can be reduced in this way. Two cases are addresses specially, replication and restart, for both of which the cache is leveraged to speed up the processing, so the reclaim is postponed to a right time. To do this, a flag is added to`rdbSave` and `rdbLoad` to control whether the cache need to be kept, with the default value false. # Something deserve noting 1. Though `posix_fadvise` is the POSIX standard, but only few platform support it, e.g. Linux, FreeBSD 10.0. 2. In Linux `posix_fadvise` only take effect on writeback-ed pages, so a `sync`(or `fsync`, `fdatasync`) is needed to flush the dirty page before `posix_fadvise` if we reclaim write cache. # About test A unit test is added to verify the effect of `posix_fadvise`. In integration test overall cache increase is checked, as well as the cache backed by RDB as a specific TCL test is executed in isolated Github action job.
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- 30 Jan, 2023 1 commit
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Qu Chen authored
Redis 7.0 introduced new logic in expireIfNeeded() where a read-only replica would never consider a key as expired when replicating commands from the master. See acf3495e. This was done by checking server.current_client with server.master. However, we should instead check for CLIENT_MASTER flag for this logic to be more robust and consistent with the rest of the Redis code base.
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- 16 Jan, 2023 1 commit
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Oran Agra authored
Related to the hang reported in #11671 Currently, redis can disconnect a client due to reaching output buffer limit, it'll also avoid feeding that output buffer with more data, but it will keep running the loop in the command (despite the client already being marked for disconnection) This PR is an attempt to mitigate the problem, specifically for commands that are easy to abuse, specifically: KEYS, HRANDFIELD, SRANDMEMBER, ZRANDMEMBER. The RAND family of commands can take a negative COUNT argument (which is not bound to the number of elements in the key), so it's enough to create a key with one field, and then these commands can be used to hang redis. For KEYS the caller can use the existing keyspace in redis (if big enough).
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- 11 Jan, 2023 2 commits
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Viktor Söderqvist authored
This change deletes the dictGetNext and dictGetNextRef functions, so the dict API doesn't expose the next field at all. The bucket function in dictScan is deleted. A separate dictScanDefrag function is added which takes a defrag alloc function to defrag-reallocate the dict entries. "Dirty" code accessing the dict internals in active defrag is removed. An 'afterReplaceEntry' is added to dictType, which allows the dict user to keep the dictEntry metadata up to date after reallocation/defrag/move. Additionally, for updating the cluster slot-to-key mapping, after a dictEntry has been reallocated, we need to know which db a dict belongs to, so we store a pointer to the db in a new metadata section in the dict struct, which is a new mechanism similar to dictEntry metadata. This adds some complexity but provides better isolation.
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Viktor Söderqvist authored
Use functions for all accesses to dictEntry (except in dict.c). Dict abuses e.g. in defrag.c have been replaced by support functions provided by dict.
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- 01 Jan, 2023 1 commit
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ranshid authored
*TL;DR* --------------------------------------- Following the discussion over the issue [#7551](https://github.com/redis/redis/issues/7551 ) We decided to refactor the client blocking code to eliminate some of the code duplications and to rebuild the infrastructure better for future key blocking cases. *In this PR* --------------------------------------- 1. reprocess the command once a client becomes unblocked on key (instead of running custom code for the unblocked path that's different than the one that would have run if blocking wasn't needed) 2. eliminate some (now) irrelevant code for handling unblocking lists/zsets/streams etc... 3. modify some tests to intercept the error in cases of error on reprocess after unblock (see details in the notes section below) 4. replace '$' on the client argv with current stream id. Since once we reprocess the stream XREAD we need to read from the last msg and not wait for new msg in order to prevent endless block loop. 5. Added statistics to the info "Clients" section to report the: * `total_blocking_keys` - number of blocking keys * `total_blocking_keys_on_nokey` - number of blocking keys which have at least 1 client which would like to be unblocked on when the key is deleted. 6. Avoid expiring unblocked key during unblock. Previously we used to lookup the unblocked key which might have been expired during the lookup. Now we lookup the key using NOTOUCH and NOEXPIRE to avoid deleting it at this point, so propagating commands in blocked.c is no longer needed. 7. deprecated command flags. We decided to remove the CMD_CALL_STATS and CMD_CALL_SLOWLOG and make an explicit verification in the call() function in order to decide if stats update should take place. This should simplify the logic and also mitigate existing issues: for example module calls which are triggered as part of AOF loading might still report stats even though they are called during AOF loading. *Behavior changes* --------------------------------------------------- 1. As this implementation prevents writing dedicated code handling unblocked streams/lists/zsets, since we now re-process the command once the client is unblocked some errors will be reported differently. The old implementation used to issue ``UNBLOCKED the stream key no longer exists`` in the following cases: - The stream key has been deleted (ie. calling DEL) - The stream and group existed but the key type was changed by overriding it (ie. with set command) - The key not longer exists after we swapdb with a db which does not contains this key - After swapdb when the new db has this key but with different type. In the new implementation the reported errors will be the same as if the command was processed after effect: **NOGROUP** - in case key no longer exists, or **WRONGTYPE** in case the key was overridden with a different type. 2. Reprocessing the command means that some checks will be reevaluated once the client is unblocked. For example, ACL rules might change since the command originally was executed and will fail once the client is unblocked. Another example is OOM condition checks which might enable the command to run and block but fail the command reprocess once the client is unblocked. 3. One of the changes in this PR is that no command stats are being updated once the command is blocked (all stats will be updated once the client is unblocked). This implies that when we have many clients blocked, users will no longer be able to get that information from the command stats. However the information can still be gathered from the client list. **Client blocking** --------------------------------------------------- the blocking on key will still be triggered the same way as it is done today. in order to block the current client on list of keys, the call to blockForKeys will still need to be made which will perform the same as it is today: * add the client to the list of blocked clients on each key * keep the key with a matching list node (position in the global blocking clients list for that key) in the client private blocking key dict. * flag the client with CLIENT_BLOCKED * update blocking statistics * register the client on the timeout table **Key Unblock** --------------------------------------------------- Unblocking a specific key will be triggered (same as today) by calling signalKeyAsReady. the implementation in that part will stay the same as today - adding the key to the global readyList. The reason to maintain the readyList (as apposed to iterating over all clients blocked on the specific key) is in order to keep the signal operation as short as possible, since it is called during the command processing. The main change is that instead of going through a dedicated code path that operates the blocked command we will just call processPendingCommandsAndResetClient. **ClientUnblock (keys)** --------------------------------------------------- 1. Unblocking clients on keys will be triggered after command is processed and during the beforeSleep 8. the general schema is: 9. For each key *k* in the readyList: ``` For each client *c* which is blocked on *k*: in case either: 1. *k* exists AND the *k* type matches the current client blocking type OR 2. *k* exists and *c* is blocked on module command OR 3. *k* does not exists and *c* was blocked with the flag unblock_on_deleted_key do: 1. remove the client from the list of clients blocked on this key 2. remove the blocking list node from the client blocking key dict 3. remove the client from the timeout list 10. queue the client on the unblocked_clients list 11. *NEW*: call processCommandAndResetClient(c); ``` *NOTE:* for module blocked clients we will still call the moduleUnblockClientByHandle which will queue the client for processing in moduleUnblockedClients list. **Process Unblocked clients** --------------------------------------------------- The process of all unblocked clients is done in the beforeSleep and no change is planned in that part. The general schema will be: For each client *c* in server.unblocked_clients: * remove client from the server.unblocked_clients * set back the client readHandler * continue processing the pending command and input buffer. *Some notes regarding the new implementation* --------------------------------------------------- 1. Although it was proposed, it is currently difficult to remove the read handler from the client while it is blocked. The reason is that a blocked client should be unblocked when it is disconnected, or we might consume data into void. 2. While this PR mainly keep the current blocking logic as-is, there might be some future additions to the infrastructure that we would like to have: - allow non-preemptive blocking of client - sometimes we can think that a new kind of blocking can be expected to not be preempt. for example lets imagine we hold some keys on disk and when a command needs to process them it will block until the keys are uploaded. in this case we will want the client to not disconnect or be unblocked until the process is completed (remove the client read handler, prevent client timeout, disable unblock via debug command etc...). - allow generic blocking based on command declared keys - we might want to add a hook before command processing to check if any of the declared keys require the command to block. this way it would be easier to add new kinds of key-based blocking mechanisms. Co-authored-by:
Oran Agra <oran@redislabs.com> Signed-off-by:
Ran Shidlansik <ranshid@amazon.com>
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- 20 Dec, 2022 1 commit
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guybe7 authored
1. Get rid of server.core_propagates - we can just rely on module/call nesting levels 2. Rename in_nested_call to execution_nesting and update the comment 3. Remove module_ctx_nesting (redundant, we can use execution_nesting) 4. Modify postExecutionUnitOperations according to the comment (The main purpose of this PR) 5. trackingHandlePendingKeyInvalidations: Check the nesting level inside this function
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- 09 Dec, 2022 1 commit
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Binbin authored
In #11290, we added listpack encoding for SET object. But forgot to support it in zuiFind, causes ZINTER, ZINTERSTORE, ZINTERCARD, ZIDFF, ZDIFFSTORE to crash. And forgot to support it in RM_ScanKey, causes it hang. This PR add support SET listpack in zuiFind, and in RM_ScanKey. And add tests for related commands to cover this case. Other changes: - There is no reason for zuiFind to go into the internals of the SET. It can simply use setTypeIsMember and don't care about encoding. - Remove the `#include "intset.h"` from server.h reduce the chance of accidental intset API use. - Move setTypeAddAux, setTypeRemoveAux and setTypeIsMemberAux interfaces to the header. - In scanGenericCommand, use setTypeInitIterator and setTypeNext to handle OBJ_SET scan. - In RM_ScanKey, improve hash scan mode, use lpGetValue like zset, they can share code and better performance. The zuiFind part fixes #11578 Co-authored-by:
Oran Agra <oran@redislabs.com> Co-authored-by:
Viktor Söderqvist <viktor.soderqvist@est.tech>
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- 30 Nov, 2022 1 commit
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Huang Zhw authored
Add a new module event `RedisModule_Event_Key`, this event is fired when a key is removed from the keyspace. The event includes an open key that can be used for reading the key before it is removed. Modules can also extract the key-name, and use RM_Open or RM_Call to access key from within that event, but shouldn't modify anything from within this event. The following sub events are available: - `REDISMODULE_SUBEVENT_KEY_DELETED` - `REDISMODULE_SUBEVENT_KEY_EXPIRED` - `REDISMODULE_SUBEVENT_KEY_EVICTED` - `REDISMODULE_SUBEVENT_KEY_OVERWRITE` The data pointer can be casted to a RedisModuleKeyInfo structure with the following fields: ``` RedisModuleKey *key; // Opened Key ``` ### internals * We also add two dict functions: `dictTwoPhaseUnlinkFind` finds an element from the table, also get the plink of the entry. The entry is returned if the element is found. The user should later call `dictTwoPhaseUnlinkFree` with it in order to unlink and release it. Otherwise if the key is not found, NULL is returned. These two functions should be used in pair. `dictTwoPhaseUnlinkFind` pauses rehash and `dictTwoPhaseUnlinkFree` resumes rehash. * We change `dbOverwrite` to `dbReplaceValue` which just replaces the value of the key and doesn't fire any events. The "overwrite" part (which emits events) is just when called from `setKey`, the other places that called dbOverwrite were ones that just update the value in-place (INCR*, SPOP, and dbUnshareStringValue). This should not have any real impact since `moduleNotifyKeyUnlink` and `signalDeletedKeyAsReady` wouldn't have mattered in these cases anyway (i.e. module keys and stream keys didn't have direct calls to dbOverwrite) * since we allow doing RM_OpenKey from withing these callbacks, we temporarily disable lazy expiry. * We also temporarily disable lazy expiry when we are in unlink/unlink2 callback and keyspace notification callback. * Move special definitions to the top of redismodule.h This is needed to resolve compilation errors with RedisModuleKeyInfoV1 that carries a RedisModuleKey member. Co-authored-by:
Oran Agra <oran@redislabs.com>
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- 09 Nov, 2022 1 commit
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Viktor Söderqvist authored
Small sets with not only integer elements are listpack encoded, by default up to 128 elements, max 64 bytes per element, new config `set-max-listpack-entries` and `set-max-listpack-value`. This saves memory for small sets compared to using a hashtable. Sets with only integers, even very small sets, are still intset encoded (up to 1G limit, etc.). Larger sets are hashtable encoded. This PR increments the RDB version, and has an effect on OBJECT ENCODING Possible conversions when elements are added: intset -> listpack listpack -> hashtable intset -> hashtable Note: No conversion happens when elements are deleted. If all elements are deleted and then added again, the set is deleted and recreated, thus implicitly converted to a smaller encoding.
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- 27 Oct, 2022 1 commit
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Moti Cohen authored
Renamed from "Pause Clients" to "Pause Actions" since the mechanism can pause several actions in redis, not just clients (e.g. eviction, expiration). Previously each pause purpose (which has a timeout that's tracked separately from others purposes), also implicitly dictated what it pauses (reads, writes, eviction, etc). Now it is explicit, and the actions that are paused (bit flags) are defined separately from the purpose. - Previously, when using feature pause-client it also implicitly means to make the server static: - Pause replica traffic - Pauses eviction processing - Pauses expire processing Making the server static is used also for failover and shutdown. This PR internally rebrand pause-client API to become pause-action API. It also Simplifies pauseClients structure by replacing pointers array with static array. The context of this PR is to add another trigger to pause-client which will activated in case of OOM as throttling mechanism ([see here](https://github.com/redis/redis/issues/10907)). In this case we want only to pause client, and eviction actions.
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- 18 Oct, 2022 1 commit
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guybe7 authored
The use case is a module that wants to implement a blocking command on a key that necessarily exists and wants to unblock the client in case the key is deleted (much like what we implemented for XREADGROUP in #10306) New module API: * RedisModule_BlockClientOnKeysWithFlags Flags: * REDISMODULE_BLOCK_UNBLOCK_NONE * REDISMODULE_BLOCK_UNBLOCK_DELETED ### Detailed description of code changes blocked.c: 1. Both module and stream functions are called whether the key exists or not, regardless of its type. We do that in order to allow modules/stream to unblock the client in case the key is no longer present or has changed type (the behavior for streams didn't change, just code that moved into serveClientsBlockedOnStreamKey) 2. Make sure afterCommand is called in serveClientsBlockedOnKeyByModule, in order to propagate actions from moduleTryServeClientBlockedOnKey. 3. handleClientsBlockedOnKeys: call propagatePendingCommands directly after lookupKeyReadWithFlags to prevent a possible lazy-expire DEL from being mixed with any command propagated by the preceding functions. 4. blockForKeys: Caller can specifiy that it wants to be awakened if key is deleted. Minor optimizations (use dictAddRaw). 5. signalKeyAsReady became signalKeyAsReadyLogic which can take a boolean in case the key is deleted. It will only signal if there's at least one client that awaits key deletion (to save calls to handleClientsBlockedOnKeys). Minor optimizations (use dictAddRaw) db.c: 1. scanDatabaseForDeletedStreams is now scanDatabaseForDeletedKeys and will signalKeyAsReady for any key that was removed from the database or changed type. It is the responsibility of the code in blocked.c to ignore or act on deleted/type-changed keys. 2. Use the new signalDeletedKeyAsReady where needed blockedonkey.c + tcl: 1. Added test of new capabilities (FSL.BPOPGT now requires the key to exist in order to work)
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