Backport pull request #125 from grooverdan/MDEV-8923_innodb_buffer_pool_dump_pct to 10.0
WL#6504 InnoDB buffer pool dump/load enchantments
This patch consists of two parts:
1. Dump only the hottest N% of the buffer pool(s)
2. Prevent hogging the server duing BP load
From MySQL - commit b409342c43ce2edb68807100a77001367c7e6b8e
Add testcases for innodb_buffer_pool_dump_pct_basic.
Part of the code authored by Daniel Black
- Added some extra command to rpl_start_stop to ensure that the
IO thread has connected to the master before we shut down the server.
- if signal returns signalhandler_t, use this with the alarm code
- Added missing tests to sys_vars
- Fixed some possible overflow bugs in tabxml.cpp
Analysis: Lengths which are not UNIV_SQL_NULL, but bigger than the following
number indicate that a field contains a reference to an externally
stored part of the field in the tablespace. The length field then
contains the sum of the following flag and the locally stored len.
This was incorrectly set to
define UNIV_EXTERN_STORAGE_FIELD (UNIV_SQL_NULL - UNIV_PAGE_SIZE_MAX)
When it should be
define UNIV_EXTERN_STORAGE_FIELD (UNIV_SQL_NULL - UNIV_PAGE_SIZE_DEF)
Additionally, we need to disable support for > 16K page size for
row compressed tables because a compressed page directory entry
reserves 14 bits for the start offset and 2 bits for flags.
This limits the uncompressed page size to 16k. To support
larger pages page directory entry needs to be larger.
Analysis: Current implementation will write and read at least one block
(sort_buffer_size bytes) from disk / index even if that block does not
contain any records.
Fix: Avoid writing / reading empty blocks to temporary files (disk).
Change session only variable enforce_storage_engine to be
session variable and make sure that also global value
is used if session variable is not set.
Added new dynamic configuration variable innodb_buf_dump_status_frequency
to configure how often buffer pool dump status is printed in the logs.
A number between [0, 100] that tells how oftern buffer pool dump status
in percentages should be printed. E.g. 10 means that buffer pool dump
status is printed when every 10% of number of buffer pool pages are
dumped. Default is 0 (only start and end status is printed).
Add log_bin_index, log_bin_basename and relay_log_basename system
variables. Also, convert relay_log_index system variable to
NO_CMD_LINE and implement --relay-log-index as a command line
option.
