* Early implementation
* Added description for gauges
* Added prometheus lib finding to Cmake
* Fixed FindProm comments
* Small changes
* free to prom_free
* Moved metrics to separate file
* Refactored & added new methods to prom_metrics
* Refactored cron.c to use prom_metrics.h
* Refactored CMake & odyssey.h
* Added new metrics
* Small refactoring
* Small method renaming
* Small fix in init
* Added methods for use in od_cron_stats_cb
* Small fixes
* Refactored metrics to use separate collectors
* Small fix
* Passing metrics to od_cron_stat_cb now.
* Removed unused imports
* Removed old od_log calls
* Removed TODO
* Revert "Removed old od_log calls"
This reverts commit 60000c8321.
* Uncommented od_log calls
* Added processed clients field to metrics
* Refactored metrics init
* Fixed write_stat
* Added method for worker stats
* Added method for worker stat to metrics header file
* Refactored worker stat method
* Reverted changes in odyssey.h
* Added writing metrics to od_worker
* Added new method to logger
Method provides writing big strings to log without formatting.
* Fixed prometheus log writing
* More fixes
* Fixed log writing
* Fixed log calls
* Added TODO
* Added assertion whether prom.h found
* Fixed no format logger method
Now logs follow log format
* Fixed logger
* Added log_stats_prom option to config
* Renamed od_logger_write_no_fmt to od_logger_write_plain
* Formatted
* More ifdefs
* Added memory deallocating in od_cron_stop
* Updated configuration.md
* Removed outdated TODO
* Changed label
* Formatted
* do not hold repilation connections while online restart
* drop connection wtih rate (no more that 1 per sec)
* fix review
* eject info per-server
* use per thread global state to smoothly eject old connection
Co-authored-by: reshke <Kirill Reshke>
Yury Frolov