- 06 Jul, 2017 1 commit
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antirez authored
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- 20 Feb, 2017 1 commit
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antirez authored
This change attempts to switch to an hash function which mitigates the effects of the HashDoS attack (denial of service attack trying to force data structures to worst case behavior) while at the same time providing Redis with an hash function that does not expect the input data to be word aligned, a condition no longer true now that sds.c strings have a varialbe length header. Note that it is possible sometimes that even using an hash function for which collisions cannot be generated without knowing the seed, special implementation details or the exposure of the seed in an indirect way (for example the ability to add elements to a Set and check the return in which Redis returns them with SMEMBERS) may make the attacker's life simpler in the process of trying to guess the correct seed, however the next step would be to switch to a log(N) data structure when too many items in a single bucket are detected: this seems like an overkill in the case of Redis. SPEED REGRESION TESTS: In order to verify that switching from MurmurHash to SipHash had no impact on speed, a set of benchmarks involving fast insertion of 5 million of keys were performed. The result shows Redis with SipHash in high pipelining conditions to be about 4% slower compared to using the previous hash function. However this could partially be related to the fact that the current implementation does not attempt to hash whole words at a time but reads single bytes, in order to have an output which is endian-netural and at the same time working on systems where unaligned memory accesses are a problem. Further X86 specific optimizations should be tested, the function may easily get at the same level of MurMurHash2 if a few optimizations are performed.
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- 18 Jan, 2017 1 commit
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antirez authored
This is of great interest because allows us to print debugging informations that could be of useful when debugging, like in the following example: serverPanic("Unexpected encoding for object %d, %d", obj->type, obj->encoding);
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- 02 Jan, 2017 1 commit
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oranagra authored
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- 30 Dec, 2016 1 commit
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oranagra authored
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- 24 Dec, 2016 1 commit
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oranagra authored
getExpire calls dictFind which can do rehashing. found by calling computeDatasetDigest from serverCron and running the test suite.
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- 16 Dec, 2016 1 commit
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antirez authored
The commit improves ziplistRepr() and adds a new debugging subcommand so that we can trigger the dump directly from the Redis API. This command capability was used while investigating issue #3684.
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- 09 Nov, 2016 1 commit
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antirez authored
The gist of the changes is that now, partial resynchronizations between slaves and masters (without the need of a full resync with RDB transfer and so forth), work in a number of cases when it was impossible in the past. For instance: 1. When a slave is promoted to mastrer, the slaves of the old master can partially resynchronize with the new master. 2. Chained slalves (slaves of slaves) can be moved to replicate to other slaves or the master itsef, without requiring a full resync. 3. The master itself, after being turned into a slave, is able to partially resynchronize with the new master, when it joins replication again. In order to obtain this, the following main changes were operated: * Slaves also take a replication backlog, not just masters. * Same stream replication for all the slaves and sub slaves. The replication stream is identical from the top level master to its slaves and is also the same from the slaves to their sub-slaves and so forth. This means that if a slave is later promoted to master, it has the same replication backlong, and can partially resynchronize with its slaves (that were previously slaves of the old master). * A given replication history is no longer identified by the `runid` of a Redis node. There is instead a `replication ID` which changes every time the instance has a new history no longer coherent with the past one. So, for example, slaves publish the same replication history of their master, however when they are turned into masters, they publish a new replication ID, but still remember the old ID, so that they are able to partially resynchronize with slaves of the old master (up to a given offset). * The replication protocol was slightly modified so that a new extended +CONTINUE reply from the master is able to inform the slave of a replication ID change. * REPLCONF CAPA is used in order to notify masters that a slave is able to understand the new +CONTINUE reply. * The RDB file was extended with an auxiliary field that is able to select a given DB after loading in the slave, so that the slave can continue receiving the replication stream from the point it was disconnected without requiring the master to insert "SELECT" statements. This is useful in order to guarantee the "same stream" property, because the slave must be able to accumulate an identical backlog. * Slave pings to sub-slaves are now sent in a special form, when the top-level master is disconnected, in order to don't interfer with the replication stream. We just use out of band "\n" bytes as in other parts of the Redis protocol. An old design document is available here: https://gist.github.com/antirez/ae068f95c0d084891305 However the implementation is not identical to the description because during the work to implement it, different changes were needed in order to make things working well.
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- 26 Sep, 2016 1 commit
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antirez authored
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- 16 Sep, 2016 2 commits
- 09 Sep, 2016 2 commits
- 08 Sep, 2016 1 commit
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oranagra authored
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- 20 Jun, 2016 1 commit
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Yossi Gottlieb authored
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- 04 May, 2016 1 commit
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antirez authored
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- 25 Apr, 2016 1 commit
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Oran Agra authored
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- 16 Dec, 2015 3 commits
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antirez authored
The old test, designed to do a transformation on the bits that was invertible, in order to avoid touching the original memory content, was not effective as it was redis-server --test-memory. The former often reported OK while the latter was able to spot the error. So the test was substituted with one that may perform better, however the new one must backup the memory tested, so it tests memory in small pieces. This limits the effectiveness because of the CPU caches. However some attempt is made in order to trash the CPU cache between the fill and the check stages, but not for the addressing test unfortunately. We'll see if this test will be able to find errors where the old failed.
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antirez authored
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antirez authored
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- 15 Dec, 2015 1 commit
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antirez authored
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- 28 Nov, 2015 1 commit
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antirez authored
There are some cases of printing unsigned integer with %d conversion specificator and vice versa (signed integer with %u specificator). Patch by Sergey Polovko. Backported to Redis from Disque.
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- 30 Oct, 2015 2 commits
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antirez authored
Make sure to flush the AOF output buffers before reloading. Result: less false timing related false positives on AOF tests.
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antirez authored
Currently this feature is only accessible via DEBUG for testing, since otherwise depending on the instance configuration a given script works or is broken, which is against the Redis philosophy.
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- 13 Oct, 2015 1 commit
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antirez authored
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- 01 Oct, 2015 5 commits
- 27 Jul, 2015 1 commit
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antirez authored
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- 26 Jul, 2015 6 commits
- 16 Jul, 2015 1 commit
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antirez authored
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- 14 Jul, 2015 2 commits