This test was failing from time to time see discussion at the bottom of #7635
This was probably due to timing, the DEBUG SLEEP executed by redis-cli
didn't sleep for enough time.
This commit changes:
1) use SET-ACTIVE-EXPIRE instead of DEBUG SLEEP
2) reduce many `after` sleeps with retry loops to speed up the test.
3) add many comment explaining the different steps of the test and
it's purpose.
4) config appendonly before populating the volatile keys, so that they'll
be part of the AOF command stream rather than the preamble RDB portion.
other complications: recently kill_instance switched from SIGKILL to
SIGTERM, and this would sometimes fail since there was an AOFRW running
in the background. now we wait for it to end before attempting the kill.
* 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.
The test works but is very slow so far, since it involves resharding
1/5 of all the cluster slots from master 0 to the other 4 masters and
back into the original master.
Now elements added to lists are incremental numbers in order to
understand, when inconsistencies are found, what is the order in which
the elements were added. Also the error now provides both the expected
and found value.
It's a key invariant that when AOF is enabled, after the cluster
reshards, a crash-recovery event causes all the keys to be still fine
with the expected logical content. Now this is part of unit 04.
The old version was modeled with two failovers, however after the first
it is possible that another slave will migrate to the new master, since
for some time the new master is not backed by any slave. Probably there
should be some pause after a failover, before the migration. Anyway the
test is simpler in this way, and depends less on timing.
In the test we use WAIT when the master and slave are up, and only later the
partition is created killing the master, so we are sure we don't incur
in failure modes that may lose writes in this test: the goal here is to
make sure that the elected slave was replicating correctly with the
master.
