In some tests, the code manually searches for a log message, and it
uses tail -1 with a delay of 1 second, which can miss the expected line.
Also, because the aof tests use start_server_aof and not start_server,
the test name doesn't log into the server log.
To fix the above, I made the following changes:
- Change the start_server_aof to wrap the start_server.
This will add the created aof server to the servers list, and make
srv() and wait_for_log_messages() available for the tests.
- Introduce a new option for start_server.
'wait_ready' - an option to let the caller start the test code without
waiting for the server to be ready. useful for tests on a server that
is expected to exit on startup.
- Create a new start_server_aof_ex.
The new proc also accept options as argument and make use of the
new 'short_life' option for tests that are expected to exit on startup
because of some error in the aof file(s).
Because of the above, I had to change many lines and replace every
local srv variable (a server config) usage with the srv().
Implement Multi-Part AOF mechanism to avoid overheads during AOFRW.
Introducing a folder with multiple AOF files tracked by a manifest file.
The main issues with the the original AOFRW mechanism are:
* buffering of commands that are processed during rewrite (consuming a lot of RAM)
* freezes of the main process when the AOFRW completes to drain the remaining part of the buffer and fsync it.
* double disk IO for the data that arrives during AOFRW (had to be written to both the old and new AOF files)
The main modifications of this PR:
1. Remove the AOF rewrite buffer and related code.
2. Divide the AOF into multiple files, they are classified as two types, one is the the `BASE` type,
it represents the full amount of data (Maybe AOF or RDB format) after each AOFRW, there is only
one `BASE` file at most. The second is `INCR` type, may have more than one. They represent the
incremental commands since the last AOFRW.
3. Use a AOF manifest file to record and manage these AOF files mentioned above.
4. The original configuration of `appendfilename` will be the base part of the new file name, for example:
`appendonly.aof.1.base.rdb` and `appendonly.aof.2.incr.aof`
5. Add manifest-related TCL tests, and modified some existing tests that depend on the `appendfilename`
6. Remove the `aof_rewrite_buffer_length` field in info.
7. Add `aof-disable-auto-gc` configuration. By default we're automatically deleting HISTORY type AOFs.
It also gives users the opportunity to preserve the history AOFs. just for testing use now.
8. Add AOFRW limiting measure. When the AOFRW failures reaches the threshold (3 times now),
we will delay the execution of the next AOFRW by 1 minute. If the next AOFRW also fails, it will be
delayed by 2 minutes. The next is 4, 8, 16, the maximum delay is 60 minutes (1 hour). During the limit
period, we can still use the 'bgrewriteaof' command to execute AOFRW immediately.
9. Support upgrade (load) data from old version redis.
10. Add `appenddirname` configuration, as the directory name of the append only files. All AOF files and
manifest file will be placed in this directory.
11. Only the last AOF file (BASE or INCR) can be truncated. Otherwise redis will exit even if
`aof-load-truncated` is enabled.
Co-authored-by: Oran Agra <oran@redislabs.com>
