1. 02 Apr, 2020 2 commits
  2. 01 Apr, 2020 6 commits
  3. 18 Dec, 2019 3 commits
  4. 09 Jan, 2019 2 commits
  5. 22 Oct, 2018 1 commit
  6. 16 Oct, 2018 1 commit
  7. 18 Jun, 2018 1 commit
  8. 13 Dec, 2016 1 commit
    • antirez's avatar
      Replication: fix the infamous key leakage of writable slaves + EXPIRE. · 04542cff
      antirez authored
      BACKGROUND AND USE CASEj
      
      Redis slaves are normally write only, however the supprot a "writable"
      mode which is very handy when scaling reads on slaves, that actually
      need write operations in order to access data. For instance imagine
      having slaves replicating certain Sets keys from the master. When
      accessing the data on the slave, we want to peform intersections between
      such Sets values. However we don't want to intersect each time: to cache
      the intersection for some time often is a good idea.
      
      To do so, it is possible to setup a slave as a writable slave, and
      perform the intersection on the slave side, perhaps setting a TTL on the
      resulting key so that it will expire after some time.
      
      THE BUG
      
      Problem: in order to have a consistent replication, expiring of keys in
      Redis replication is up to the master, that synthesize DEL operations to
      send in the replication stream. However slaves logically expire keys
      by hiding them from read attempts from clients so that if the master did
      not promptly sent a DEL, the client still see logically expired keys
      as non existing.
      
      Because slaves don't actively expire keys by actually evicting them but
      just masking from the POV of read operations, if a key is created in a
      writable slave, and an expire is set, the key will be leaked forever:
      
      1. No DEL will be received from the master, which does not know about
      such a key at all.
      
      2. No eviction will be performed by the slave, since it needs to disable
      eviction because it's up to masters, otherwise consistency of data is
      lost.
      
      THE FIX
      
      In order to fix the problem, the slave should be able to tag keys that
      were created in the slave side and have an expire set in some way.
      
      My solution involved using an unique additional dictionary created by
      the writable slave only if needed. The dictionary is obviously keyed by
      the key name that we need to track: all the keys that are set with an
      expire directly by a client writing to the slave are tracked.
      
      The value in the dictionary is a bitmap of all the DBs where such a key
      name need to be tracked, so that we can use a single dictionary to track
      keys in all the DBs used by the slave (actually this limits the solution
      to the first 64 DBs, but the default with Redis is to use 16 DBs).
      
      This solution allows to pay both a small complexity and CPU penalty,
      which is zero when the feature is not used, actually. The slave-side
      eviction is encapsulated in code which is not coupled with the rest of
      the Redis core, if not for the hook to track the keys.
      
      TODO
      
      I'm doing the first smoke tests to see if the feature works as expected:
      so far so good. Unit tests should be added before merging into the
      4.0 branch.
      04542cff
  9. 15 Jun, 2016 1 commit
  10. 27 Jul, 2015 1 commit
  11. 26 Jul, 2015 4 commits
  12. 03 Feb, 2015 1 commit
  13. 14 Dec, 2014 1 commit
    • Mihir Joshi's avatar
      Stricter options for SET command · 352172a7
      Mihir Joshi authored
      - As per Antirez's suggestion, this commit raises an error when mutually
      exclusive options are provided. Duplicate options are allowed.
      352172a7
  14. 11 Dec, 2014 1 commit
    • Matt Stancliff's avatar
      Bitops: Stop overallocating storage space on set · badf0f00
      Matt Stancliff authored
      Previously the string was created empty then re-sized
      to fit the offset, but sds resize causes the sds to
      over-allocate by at least 1 MB (which is a lot when
      you are operating at bit-level access).
      
      This also improves the speed of initial sets by 2% to 6%
      based on quick testing.
      
      Patch logic provided by @oranagra
      
      Fixes #1918
      badf0f00
  15. 02 Dec, 2014 1 commit
  16. 22 Nov, 2014 1 commit
    • Mihir Joshi's avatar
      stricter options for SET command · e9b014cf
      Mihir Joshi authored
      Issue: #2157
      As the SET command is parsed, it remembers which options are already set
      and if a duplicate option is found, raises an error because it is
      essentially an invalid syntax.
      
      It still allows mutually exclusive options like EX and PX because taking
      an option over another (precedence) is not essentially a syntactic
      error.
      e9b014cf
  17. 03 Oct, 2014 1 commit
    • antirez's avatar
      INCR: Modify incremented object in-place when possible. · 16559b46
      antirez authored
      However we don't try to do this if the integer is already inside a range
      representable with a shared integer.
      
      The performance gain appears to be around ~15% in micro benchmarks,
      however in the long run this also helps to improve locality, so should
      have more, hard to measure, benefits.
      16559b46
  18. 02 Sep, 2014 2 commits
    • Matt Stancliff's avatar
      Return empty string if GETRANGE of empty string · b20df972
      Matt Stancliff authored
      Previously, GETRANGE of a key containing nothing ("")
      would allocate a large (size_t)-1 return value causing
      crashes on 32bit builds when it tried to allocate the
      4 GB return string.
      b20df972
    • Matt Stancliff's avatar
      Increase size of range request in getrange · f0e306f4
      Matt Stancliff authored
      32 bit builds don't have a big enough long to capture
      the same range as a 64 bit build.  If we use "long long"
      we get proper size limits everywhere.
      
      Also updates size of unsigned comparison to fit new size of `end`.
      
      Fixes #1981
      f0e306f4
  19. 18 Aug, 2014 1 commit
  20. 07 Aug, 2014 1 commit
    • Jan-Erik Rediger's avatar
      Handle large getrange requests · 53fdfda9
      Jan-Erik Rediger authored
      Previously the end was casted to a smaller type
      which resulted in a wrong check and failed
      with values larger than handled by unsigned.
      
      Closes #1847, #1844
      53fdfda9
  21. 30 Mar, 2014 1 commit
    • antirez's avatar
      String value unsharing refactored into proper function. · 543ede03
      antirez authored
      All the Redis functions that need to modify the string value of a key in
      a destructive way (APPEND, SETBIT, SETRANGE, ...) require to make the
      object unshared (if refcount > 1) and encoded in raw format (if encoding
      is not already REDIS_ENCODING_RAW).
      
      This was cut & pasted many times in multiple places of the code. This
      commit puts the small logic needed into a function called
      dbUnshareStringValue().
      543ede03
  22. 22 Jul, 2013 1 commit
    • antirez's avatar
      Introduction of a new string encoding: EMBSTR · 894eba07
      antirez authored
      Previously two string encodings were used for string objects:
      
      1) REDIS_ENCODING_RAW: a string object with obj->ptr pointing to an sds
      stirng.
      
      2) REDIS_ENCODING_INT: a string object where the obj->ptr void pointer
      is casted to a long.
      
      This commit introduces a experimental new encoding called
      REDIS_ENCODING_EMBSTR that implements an object represented by an sds
      string that is not modifiable but allocated in the same memory chunk as
      the robj structure itself.
      
      The chunk looks like the following:
      
      +--------------+-----------+------------+--------+----+
      | robj data... | robj->ptr | sds header | string | \0 |
      +--------------+-----+-----+------------+--------+----+
                           |                       ^
                           +-----------------------+
      
      The robj->ptr points to the contiguous sds string data, so the object
      can be manipulated with the same functions used to manipulate plan
      string objects, however we need just on malloc and one free in order to
      allocate or release this kind of objects. Moreover it has better cache
      locality.
      
      This new allocation strategy should benefit both the memory usage and
      the performances. A performance gain between 60 and 70% was observed
      during micro-benchmarks, however there is more work to do to evaluate
      the performance impact and the memory usage behavior.
      894eba07
  23. 29 Mar, 2013 1 commit
  24. 28 Mar, 2013 1 commit
  25. 28 Jan, 2013 3 commits