MDEV-27095 spider should be installed with INSTALL SONAME ha_spider
There are several plugins in ha_spider: spider, spider_alloc_mem,
spider_wrapper_protocols, spider_rewrite etc.
INSTALL PLUGIN foo SONAME ha_spider causes all the other ones to be
installed by the init queries where foo is any of the plugins.
This introduces unnecessary complexiy. For example it reads
mysql.plugins to find all other plugins, causing the hack of moving
spider plugin init to a separate thread.
To install all spider related plugins, install soname ha_spider should
be used instead.
MDEV-29676 refactored and documented spider_get_share() and friends
Extracted out common subroutines, gave more meaningful names etc,
added comments etc.
Also:
- Documented active servers load balancing reads, and other fields in
SPIDER_SHARE etc.
- Removed commented out code
- Documented and refactored self-reference check
- Removed some unnecessary functions
- Renamed unhelpful root_count
- Refactored spider_get_{sts,crd}, where we turn get_type into an enum
- Cleaned up spider_mbase_handler::show_table_status() and
spider_mbase_handler::show_index()
MDEV-27912 Fixing inconsistency w.r.t. expect files in tests.
mtr uses group suffix, but some existing inc and test files use
server_id for expect files. This patch aims to fix that.
For spider:
With this change we will not have to maintain a separate version of
restart_mysqld.inc for spider, that duplicates code, just because
spider tests use different names for expect files, and shutdown_mysqld
requires magical names for them.
With this change spider tests will also be able to use other features
provided by restart_mysqld.inc without code duplication, like the
parameter $restart_parameters (see e.g. the testcase mdev_29904.test
in commit ef1161e5d4f).
Tests run after this change: default, spider, rocksdb, galera, using
the following command