MDEV-32157 MDEV-28856 Spider: Tests, documentation, small fixes and cleanups
Removed some redundant hint related string literals from
spd_db_conn.cc
Clean up SPIDER_PARAM_*_[CHAR]LEN[S]
Adding tests covering monitoring_kind=2. What it does is that it reads
from mysql.spider_link_mon_servers with matching db_name, table_name,
link_id, and does not do anything about that...
How monitoring_* can be useful: in the deprecated spider high
availability feature, when one remote fails, spider will try another
remote, which apparently makes use of these table parameters.
A test covering the query_cache_sync table param. Some further tests
on some spider table params.
Wrapper should be case insensitive.
Code documentation on spider priority binary tree.
Add an assertion that static_key_cardinality is always -1. All tests
pass still
MDEV-32157 MDEV-28856 Spider: drop server in tests
This helps eliminate "server exists" failures
Also, spider/bugfix.mdev_29676, when enabled after MDEV-29525 is
pushed will fail because we have not --recorded the result. But the
failure will only emerge when working on MDEV-31138 where we manually
re-enable this test, so let's worry about that then.
Spider connection string is a comma-separated parameter definitions,
where each definition is of the form "<param_title> <param_value>",
where <param_value> is quote delimited on both ends, with backslashes
acting as an escaping prefix.
Despite the simple syntax, the existing spider connection string
parser was poorly-written, complex, hard to reason and error-prone,
causing issues like the one described in MDEV-31117. For example it
treated param title the same way as param value when assigning, and
have nonsensical fields like delim_title_len and delim_title.
Thus as part of the bugfix, we clean up the spider comment connection
string parsing, including:
- Factoring out some code from the parsing function
- Simplify the struct `st_spider_param_string_parse`
- And any necessary changes caused by the above changes
