redict/tests/support
Viktor Söderqvist 45a155bd0f
Wait for replicas when shutting down (#9872)
To avoid data loss, this commit adds a grace period for lagging replicas to
catch up the replication offset.

Done:

* Wait for replicas when shutdown is triggered by SIGTERM and SIGINT.

* Wait for replicas when shutdown is triggered by the SHUTDOWN command. A new
  blocked client type BLOCKED_SHUTDOWN is introduced, allowing multiple clients
  to call SHUTDOWN in parallel.
  Note that they don't expect a response unless an error happens and shutdown is aborted.

* Log warning for each replica lagging behind when finishing shutdown.

* CLIENT_PAUSE_WRITE while waiting for replicas.

* Configurable grace period 'shutdown-timeout' in seconds (default 10).

* New flags for the SHUTDOWN command:

    - NOW disables the grace period for lagging replicas.

    - FORCE ignores errors writing the RDB or AOF files which would normally
      prevent a shutdown.

    - ABORT cancels ongoing shutdown. Can't be combined with other flags.

* New field in the output of the INFO command: 'shutdown_in_milliseconds'. The
  value is the remaining maximum time to wait for lagging replicas before
  finishing the shutdown. This field is present in the Server section **only**
  during shutdown.

Not directly related:

* When shutting down, if there is an AOF saving child, it is killed **even** if AOF
  is disabled. This can happen if BGREWRITEAOF is used when AOF is off.

* Client pause now has end time and type (WRITE or ALL) per purpose. The
  different pause purposes are *CLIENT PAUSE command*, *failover* and
  *shutdown*. If clients are unpaused for one purpose, it doesn't affect client
  pause for other purposes. For example, the CLIENT UNPAUSE command doesn't
  affect client pause initiated by the failover or shutdown procedures. A completed
  failover or a failed shutdown doesn't unpause clients paused by the CLIENT
  PAUSE command.

Notes:

* DEBUG RESTART doesn't wait for replicas.

* We already have a warning logged when a replica disconnects. This means that
  if any replica connection is lost during the shutdown, it is either logged as
  disconnected or as lagging at the time of exit.

Co-authored-by: Oran Agra <oran@redislabs.com>
2022-01-02 09:50:15 +02:00
..
benchmark.tcl Added URI support to redis-benchmark (cli and benchmark share the same uri-parsing methods) (#9314) 2021-09-14 19:45:06 +03:00
cli.tcl Improve bind and protected-mode config handling. (#9034) 2021-06-22 12:50:17 +03:00
cluster.tcl Add support for plaintext clients in TLS cluster (#8587) 2021-03-30 23:11:32 +03:00
redis.tcl Add support for list type to store elements larger than 4GB (#9357) 2021-11-03 20:47:18 +02:00
server.tcl Wait for replicas when shutting down (#9872) 2022-01-02 09:50:15 +02:00
test.tcl resolve replication test timing sensitivity - 2nd attempt (#9988) 2021-12-22 23:37:12 +02:00
tmpfile.tcl Initial implementation of a client-server parallel testing system for Redis in order to speedup execution of the test suite. 2011-07-10 23:25:48 +02:00
util.tcl Wait for replicas when shutting down (#9872) 2022-01-02 09:50:15 +02:00