Hi, Daniel Vratil from Akonadi (a PIM manager for KDE) has asked me at FOSDEM about optimal MariaDB configuration for Akonadi. Some specific questions: * innodb_flush_log_at_trx_commit. Currently, Akonadi uses innodb_flush_log_at_trx_commit=2 which as far as I understand can cause up to 1 second of changes to be lost. Using value of 1 (always flush on commit) should be safer, but maybe it would put an unnecessary load on the system? Akonadi's use case has a bit different idea of what load is - there is only one person making changes, but the system is likely to be a laptop where one cares about battery life, etc. * innodb_buffer_pool_size=80M. The dataset size can vary from very small to up to 1-1.5Gb. Some users have very little data and complain that 80M is too much. Does anybody have an experience with using very small innodb_buffer_pool_size? Please find the full config file below: === Akonadi configuration file === # These settings can be adjusted using $HOME/.config/akonadi/mysql-local.conf # # Based on advice by Kris Köhntopp # [mysqld] # strict query parsing/interpretation # TODO: make Akonadi work with those settings enabled # sql_mode=strict_trans_tables,strict_all_tables,strict_error_for_division_by_zero,no_auto_create_user,no_auto_value_on_zero,no_engine_substitution,no_zero_date,no_zero_in_date,only_full_group_by,pipes_as_concat # sql_mode=strict_trans_tables # DEBUGGING: # log all queries, useful for debugging but generates an enormous amount of data # log=mysql.full # log queries slower than n seconds, log file name relative to datadir (for debugging only) # log_slow_queries=mysql.slow # long_query_time=1 # log queries not using indices, debug only, disable for production use # log_queries_not_using_indexes=1 # # mesure database size and adjust innodb_buffer_pool_size # SELECT sum(data_length) as bla, sum(index_length) as blub FROM information_schema.tables WHERE table_schema not in ("mysql", "information_schema"); # NOTES: # Keep Innob_log_waits and keep Innodb_buffer_pool_wait_free small (see show global status like "inno%", show global variables) #expire_logs_days=3 #sync_bin_log=0 # Use UTF-8 encoding for tables character_set_server=utf8 collation_server=utf8_general_ci # use InnoDB for transactions and better crash recovery default_storage_engine=innodb # memory pool InnoDB uses to store data dictionary information and other internal data structures (default:1M) # Deprecated in MySQL >= 5.6.3 innodb_additional_mem_pool_size=1M # memory buffer InnoDB uses to cache data and indexes of its tables (default:128M) # Larger values means less I/O innodb_buffer_pool_size=80M # Create a .ibd file for each table (default:0) innodb_file_per_table=1 # Write out the log buffer to the log file at each commit (default:1) innodb_flush_log_at_trx_commit=2 # Buffer size used to write to the log files on disk (default:1M for builtin, 8M for plugin) # larger values means less I/O innodb_log_buffer_size=1M # Size of each log file in a log group (default:5M) larger means less I/O but more time for recovery. innodb_log_file_size=64M # # error log file name, relative to datadir (default:hostname.err) log_error=mysql.err # print warnings and connection errors (default:1) log_warnings=2 # Convert table named to lowercase lower_case_table_names=1 # Maximum size of one packet or any generated/intermediate string. (default:1M) max_allowed_packet=32M # Maximum simultaneous connections allowed (default:100) max_connections=256 # The two options below make no sense with prepared statements and/or transactions # (make sense when having the same query multiple times) # Memory allocated for caching query results (default:0 (disabled)) query_cache_size=0 # Do not cache results (default:1) query_cache_type=0 # Do not use the privileges mechanisms skip_grant_tables # Do not listen for TCP/IP connections at all skip_networking # The number of open tables for all threads. (default:64) table_open_cache=200 # How many threads the server should cache for reuse (default:0) thread_cache_size=3 # wait 365d before dropping the DB connection (default:8h) wait_timeout=31536000 # We use InnoDB, so don't let MyISAM eat up memory key_buffer_size=16K [client] default-character-set=utf8 BR Sergei -- Sergei Petrunia, Software Developer MariaDB | Skype: sergefp | Blog: http://s.petrunia.net/blog