PT-2168 pt-osc shouldnt fail while unable to monitor a replica node (#676)

* PT-2168 - PT-OSC shouldn't fail while unable to monitor a replica node

- Proof of concept
- Fixed regular expression in lib/TableParser.pm mistakenly chaged in the tool's code

* PT-2168 - PT-OSC shouldn't fail while unable to monitor a replica node

- Added basic test case for PT-2168
- Added more details for replica lag information
- Disconnecting replica if lag is not checked. This prevents "Too many
  connections" error

* PT-2168 - PT-OSC shouldn't fail while unable to monitor a replica node

- Implemented option --wait-lost-replicas for pt-osc, added test case

* PT-2168 - PT-OSC shouldn't fail while unable to monitor a replica node

- Added more tests for situations where connection to the replica can
  fail

* PT-2168 - PT-OSC shouldn't fail while unable to monitor a replica node

- Removed extra checks for wait_no_die variable
- Added test cases for SQL queries that pt-osc sends to replicas

* PT-2168 - PT-OSC shouldn't fail while unable to monitor a replica node

- Allow to reload dsns table while waiting for missed replica if
  --recursion-method is dsn
- Fixed logic in replica rediscovery, so it works with replicas on the
  same host but with different ports
- Renamed option wait-lost-replicas to fail-on-stopped-replication, so
  it is in line with pt-table-checksum
- Adjusted tests
- Removed debug code for PT-1760
- Added test case for PT-1760
- Added exception for variable Open_tables_with_triggers in
  lib/bash/collect.sh due to failed test in Percona Server 8.0.34+
- Updated pt-stalk

* PT-2168 - PT-OSC shouldn't fail while unable to monitor a replica node

- Updated modules
- Fixed typo in t/pt-table-sync/bidirectional.t
- Removed trailing whitespaces in lib/MasterSlave.pm

* PT-2168 - PT-OSC shouldn't fail while unable to monitor a replica node

- Help for option --fail-on-stopped-replication

* PT-2168 - PT-OSC shouldn't fail while unable to monitor a replica node

- Added check for availability of the simple_rewrite_plugin in t/pt-online-schema-change/pt-2168.t

* PT-2168 - PT-OSC shouldn't fail while unable to monitor a replica node

- Added link to the simple_rewrite_plugin source code
- Removed tests for code that runs only in the beginning of pt-osc
  action, so should not be affected by the option fail-on-stopped-replication

t/lib/bash/collect.sh

@@ -30,6 +30,8 @@ collect "$PT_TMPDIR/collect" "2011_12_05" > $p-output 2>&1
 
 wait_for_files "$p-hostname" "$p-opentables2" "$p-variables" "$p-df" "$p-innodbstatus2"
 
+cat "$p-opentables2" > /tmp/collect.test
+
 # Even if this system doesn't have all the cmds, collect should still
 # have created some files for cmds that (hopefully) all systems have.
 ls -1 $PT_TMPDIR/collect | sort > $PT_TMPDIR/collect-files