Replication client no longer checks incoming command length against the client-query-buffer-limit. This makes the master able to replicate commands longer than replica's configured client-query-buffer-limit
# replication-3.tcl
had a test timeout failure with valgrind on daily CI:
```
*** [err]: SLAVE can reload "lua" AUX RDB fields of duplicated scripts in tests/integration/replication-3.tcl
Replication not started.
```
replication took more than 70 seconds.
https://github.com/redis/redis/runs/2854037905?check_suite_focus=true
on my machine it takes only about 30, but i can see how 50 seconds isn't enough.
# replication.tcl
loading was over too quickly in freebsd daily CI:
```
*** [err]: slave fails full sync and diskless load swapdb recovers it in tests/integration/replication.tcl
Expected '0' to be equal to '1' (context: type eval line 44 cmd {assert_equal [s -1 loading] 1} proc ::start_server)
```
# rdb.tcl
loading was over too quickly.
increase the time loading takes, and decrease the amount of work we try to achieve in that time.
This commit revives the improves the ability to run the test suite against
external servers, instead of launching and managing `redis-server` processes as
part of the test fixture.
This capability existed in the past, using the `--host` and `--port` options.
However, it was quite limited and mostly useful when running a specific tests.
Attempting to run larger chunks of the test suite experienced many issues:
* Many tests depend on being able to start and control `redis-server` themselves,
and there's no clear distinction between external server compatible and other
tests.
* Cluster mode is not supported (resulting with `CROSSSLOT` errors).
This PR cleans up many things and makes it possible to run the entire test suite
against an external server. It also provides more fine grained controls to
handle cases where the external server supports a subset of the Redis commands,
limited number of databases, cluster mode, etc.
The tests directory now contains a `README.md` file that describes how this
works.
This commit also includes additional cleanups and fixes:
* Tests can now be tagged.
* Tag-based selection is now unified across `start_server`, `tags` and `test`.
* More information is provided about skipped or ignored tests.
* Repeated patterns in tests have been extracted to common procedures, both at a
global level and on a per-test file basis.
* Cleaned up some cases where test setup was based on a previous test executing
(a major anti-pattern that repeats itself in many places).
* Cleaned up some cases where test teardown was not part of a test (in the
future we should have dedicated teardown code that executes even when tests
fail).
* Fixed some tests that were flaky running on external servers.
* fix memlry leaks with diskless replica short read.
* fix a few timing issues with valgrind runs
* fix issue with valgrind and watchdog schedule signal
about the valgrind WD issue:
the stack trace test in logging.tcl, has issues with valgrind:
==28808== Can't extend stack to 0x1ffeffdb38 during signal delivery for thread 1:
==28808== too small or bad protection modes
it seems to be some valgrind bug with SA_ONSTACK.
SA_ONSTACK seems unneeded since WD is not recursive (SA_NODEFER was removed),
also, not sure if it's even valid without a call to sigaltstack()
