1. 27 Apr, 2020 1 commit
    • Oran Agra's avatar
      Keep track of meaningful replication offset in replicas too · 4447ddc8
      Oran Agra authored
      Now both master and replicas keep track of the last replication offset
      that contains meaningful data (ignoring the tailing pings), and both
      trim that tail from the replication backlog, and the offset with which
      they try to use for psync.
      
      the implication is that if someone missed some pings, or even have
      excessive pings that the promoted replica has, it'll still be able to
      psync (avoid full sync).
      
      the downside (which was already committed) is that replicas running old
      code may fail to psync, since the promoted replica trims pings form it's
      backlog.
      
      This commit adds a test that reproduces several cases of promotions and
      demotions with stale and non-stale pings
      
      Background:
      The mearningful offset on the master was added recently to solve a problem were
      the master is left all alone, injecting PINGs into it's backlog when no one is
      listening and then gets demoted and tries to replicate from a replica that didn't
      have any of the PINGs (or at least not the last ones).
      
      however, consider this case:
      master A has two replicas (B and C) replicating directly from it.
      there's no traffic at all, and also no network issues, just many pings in the
      tail of the backlog. now B gets promoted, A becomes a replica of B, and C
      remains a replica of A. when A gets demoted, it trims the pings from its
      backlog, and successfully replicate from B. however, C is still aware of
      these PINGs, when it'll disconnect and re-connect to A, it'll ask for something
      that's not in the backlog anymore (since A trimmed the tail of it's backlog),
      and be forced to do a full sync (something it didn't have to do before the
      meaningful offset fix).
      
      Besides that, the psync2 test was always failing randomly here and there, it
      turns out the reason were PINGs. Investigating it shows the following scenario:
      
      cycle 1: redis #1 is master, and all the rest are direct replicas of #1
      cycle 2: redis #2 is promoted to master, #1 is a replica of #2 and #3 is replica of #1
      now we see that when #1 is demoted it prints:
      17339:S 21 Apr 2020 11:16:38.523 * Using the meaningful offset 3929963 instead of 3929977 to exclude the final PINGs (14 bytes difference)
      17339:S 21 Apr 2020 11:16:39.391 * Trying a partial resynchronization (request e2b3f8817735fdfe5fa4626766daa938b61419e5:3929964).
      17339:S 21 Apr 2020 11:16:39.392 * Successful partial resynchronization with master.
      and when #3 connects to the demoted #2, #2 says:
      17339:S 21 Apr 2020 11:16:40.084 * Partial resynchronization not accepted: Requested offset for secondary ID was 3929978, but I can reply up to 3929964
      
      so the issue here is that the meaningful offset feature saved the day for the
      demoted master (since it needs to sync from a replica that didn't get the last
      ping), but it didn't help one of the other replicas which did get the last ping.
      4447ddc8
  2. 25 Mar, 2020 1 commit
  3. 05 Mar, 2020 1 commit
    • Oran Agra's avatar
      fix for flaky psync2 test · 27641ee4
      Oran Agra authored
      *** [err]: PSYNC2: total sum of full synchronizations is exactly 4 in tests/integration/psync2.tcl
      Expected 5 == 4 (context: type eval line 6 cmd {assert {$sum == 4}} proc ::test)
      
      issue was that sometime the test got an unexpected full sync since it
      tried to switch to the replica before it was in sync with it's master.
      27641ee4
  4. 18 Dec, 2019 1 commit
  5. 09 Oct, 2019 1 commit
  6. 07 Oct, 2019 4 commits
    • Yossi Gottlieb's avatar
      TLS: Configuration options. · 61733ded
      Yossi Gottlieb authored
      Add configuration options for TLS protocol versions, ciphers/cipher
      suites selection, etc.
      61733ded
    • Oran Agra's avatar
      TLS: Implement support for write barrier. · 6b629480
      Oran Agra authored
      6b629480
    • Oran Agra's avatar
      diskless replication rdb transfer uses pipe, and writes to sockets form the parent process. · 5a477946
      Oran Agra authored
      misc:
      - handle SSL_has_pending by iterating though these in beforeSleep, and setting timeout of 0 to aeProcessEvents
      - fix issue with epoll signaling EPOLLHUP and EPOLLERR only to the write handlers. (needed to detect the rdb pipe was closed)
      - add key-load-delay config for testing
      - trim connShutdown which is no longer needed
      - rioFdsetWrite -> rioFdWrite - simplified since there's no longer need to write to multiple FDs
      - don't detect rdb child exited (don't call wait3) until we detect the pipe is closed
      - Cleanup bad optimization from rio.c, add another one
      5a477946
    • Yossi Gottlieb's avatar
      TLS: Connections refactoring and TLS support. · b087dd1d
      Yossi Gottlieb authored
      * Introduce a connection abstraction layer for all socket operations and
      integrate it across the code base.
      * Provide an optional TLS connections implementation based on OpenSSL.
      * Pull a newer version of hiredis with TLS support.
      * Tests, redis-cli updates for TLS support.
      b087dd1d
  7. 26 Sep, 2019 1 commit
  8. 17 Jul, 2019 1 commit
    • Oran Agra's avatar
      prevent diskless replica from terminating on short read · c56b4ddc
      Oran Agra authored
      now that replica can read rdb directly from the socket, it should avoid exiting
      on short read and instead try to re-sync.
      
      this commit tries to have minimal effects on non-diskless rdb reading.
      and includes a test that tries to trigger this scenario on various read cases.
      c56b4ddc
  9. 08 Jul, 2019 1 commit
    • Oran Agra's avatar
      diskless replication on slave side (don't store rdb to file), plus some other related fixes · 2de544cf
      Oran Agra authored
      The implementation of the diskless replication was currently diskless only on the master side.
      The slave side was still storing the received rdb file to the disk before loading it back in and parsing it.
      
      This commit adds two modes to load rdb directly from socket:
      1) when-empty
      2) using "swapdb"
      the third mode of using diskless slave by flushdb is risky and currently not included.
      
      other changes:
      --------------
      distinguish between aof configuration and state so that we can re-enable aof only when sync eventually
      succeeds (and not when exiting from readSyncBulkPayload after a failed attempt)
      also a CONFIG GET and INFO during rdb loading would have lied
      
      When loading rdb from the network, don't kill the server on short read (that can be a network error)
      
      Fix rdb check when performed on preamble AOF
      
      tests:
      run replication tests for diskless slave too
      make replication test a bit more aggressive
      Add test for diskless load swapdb
      2de544cf
  10. 05 May, 2019 1 commit
    • Oran Agra's avatar
      make replication tests more stable on slow machines · ba809f26
      Oran Agra authored
      solving few replication related tests race conditions which fail on slow machines
      
      bugfix in slave buffers test: since the test is executed twice, each time with
      a different commands count, the threshold for the delta can't be a constant.
      ba809f26
  11. 12 Dec, 2018 1 commit
  12. 11 Sep, 2018 1 commit
  13. 31 Aug, 2018 1 commit
  14. 31 Jul, 2018 1 commit
  15. 03 Jul, 2018 1 commit
  16. 27 Jun, 2018 2 commits
  17. 19 Jun, 2018 1 commit
  18. 15 May, 2018 2 commits
  19. 25 Mar, 2018 1 commit
  20. 24 Jan, 2018 1 commit
  21. 04 Dec, 2017 1 commit
  22. 30 Nov, 2017 1 commit
  23. 28 Apr, 2017 2 commits
  24. 14 Apr, 2017 1 commit
  25. 22 Feb, 2017 2 commits
    • antirez's avatar
      Solaris fixes about tail usage and atomic vars. · 95883313
      antirez authored
      Testing with Solaris C compiler (SunOS 5.11 11.2 sun4v sparc sun4v)
      there were issues compiling due to atomicvar.h and running the
      tests also failed because of "tail" usage not conform with Solaris
      tail implementation. This commit fixes both the issues.
      95883313
    • antirez's avatar
      Test: replication-psync, wait more to detect write load. · 2b36706a
      antirez authored
      Slow systems like the original Raspberry PI need more time
      than 5 seconds to start the script and detect writes.
      After fixing the Raspberry PI can pass the unit without issues.
      2b36706a
  26. 13 Dec, 2016 1 commit
  27. 29 Nov, 2016 3 commits
  28. 28 Nov, 2016 2 commits
    • antirez's avatar
      PSYNC2: stop sending newlines to sub-slaves when master is down. · eab865a0
      antirez authored
      This actually includes two changes:
      
      1) No newlines to take the master-slave link up when the upstream master
      is down. Doing this is dangerous because the sub-slave often is received
      replication protocol for an half-command, so can't receive newlines
      without desyncing the replication link, even with the code in order to
      cancel out the bytes that PSYNC2 was using. Moreover this is probably
      also not needed/sane, because anyway the slave can keep serving
      requests, and because if it's configured to don't serve stale data, it's
      a good idea, actually, to break the link.
      
      2) When a +CONTINUE with a different ID is received, we now break
      connection with the sub-slaves: they need to be notified as well. This
      was part of the original specification but for some reason it was not
      implemented in the code, and was alter found as a PSYNC2 bug in the
      integration testing.
      eab865a0
    • antirez's avatar
      PSYNC2: Test (WIP). · 16559a02
      antirez authored
      This is the PSYNC2 test that helped find issues in the code, and that
      still can show a protocol desync from time to time. Work is in progress
      in order to find the issue. For now the test is not enabled in "make
      test" and must be run manually.
      16559a02
  29. 04 Jul, 2016 1 commit
  30. 15 Oct, 2015 1 commit