Database
From OpenStreetMap
The database is a key component of OpenStreetMap, because obviously it's where we keep all our data i.e. the maps, in their most raw form.
The database is (for most purposes) accessed via the API. People interested in developing OSM applications should generally refer to the API page. Or you may be interested in Planet.osm dump downloads. If you want learn more about the way we internally represent maps see the Database schema page.
There are many things that could be improved in the database, like not even using MySQL. This page is to help developers hack on these things.
Contents |
MySQL server
The database is a MySQL server. This is running on a separate machine 'db.openstreetmap.org', a Dual core Athlon 64 running at 2.6Ghz with 8GB RAM. See Servers/db for more details. Also Nick Hill knows more.
Data statistics
Access logs
By piping OSM's Apache log through this script
we anonymise access data. Each line is a standard (well, whatever Debian ships with) format Apache log. Instead of the IP address there is an MD5SUM (Column 0) and instead of the username there is an MD5SUM (Column 2). These are calculated using a salt value. The result is a week of API access data:
- http://steve.dev.openstreetmap.org/osm-api.anony.gz (contains some data from March 2007).
Please play with it, make visualisation, statistics to your hearts content and post them here :-)
Other stats
As with all Servers we have munin stats for db.openstreetmap.org (realtime graphs showing server resource usage)
MySQL Config
Here's the current my.cnf settings as of 2007-09-24:
# # The MySQL database server configuration file. # # You can copy this to one of: # - "/etc/mysql/my.cnf" to set global options, # - "/var/lib/mysql/my.cnf" to set server-specific options or # - "~/.my.cnf" to set user-specific options. # # One can use all long options that the program supports. # Run program with --help to get a list of available options and with # --print-defaults to see which it would actually understand and use. # # For explanations see # http://dev.mysql.com/doc/mysql/en/server-system-variables.html # This will be passed to all mysql clients # It has been reported that passwords should be enclosed with ticks/quotes # escpecially if they contain "#" chars... # Remember to edit /etc/mysql/debian.cnf when changing the socket location. [client] port = 3306 socket = /var/run/mysqld/mysqld.sock # Here is entries for some specific programs # The following values assume you have at least 32M ram # This was formally known as [safe_mysqld]. Both versions are currently parsed. [mysqld_safe] socket = /var/run/mysqld/mysqld.sock nice = 0 [mysqld] # # * Basic Settings # user = mysql pid-file = /var/run/mysqld/mysqld.pid socket = /var/run/mysqld/mysqld.sock port = 3306 #basedir = /usr/local/mysql #datadir = /var/lib/mysql datadir = /data/mysql tmpdir = /tmp #language = /usr/local/mysql/share/mysql/english thread_cache_size = 16 skip-external-locking thread_concurrency = 4 # # For compatibility to other Debian packages that still use # libmysqlclient10 and libmysqlclient12. old_passwords = 1 # # Instead of skip-networking the default is now to listen only on # localhost which is more compatible and is not less secure. #bind-address = 127.0.0.1 # # * Fine Tuning # key_buffer = 2G max_allowed_packet = 16M thread_stack = 128K # # * Query Cache Configuration # query_cache_limit = 1048576 query_cache_size = 64M query_cache_type = 1 # # * Logging and Replication # # Both location gets rotated by the cronjob. # Be aware that this log type is a performance killer. #log = /var/log/mysql.log #log = /var/log/mysql/mysql.log # # Error logging goes to syslog. This is a Debian improvement :) # # Here you can see queries with especially long duration log-slow-queries = /var/log/mysql/mysql-slow.log # # The following can be used as easy to replay backup logs or for replication. server-id = 1 log-bin = /var/log/mysql/mysql-bin.log # See /etc/mysql/debian-log-rotate.conf for the number of files kept. max_binlog_size = 104857600 binlog-do-db = openstreetmap #binlog-ignore-db = include_database_name # # * BerkeleyDB # # According to an MySQL employee the use of BerkeleyDB is now discouraged # and support for it will probably cease in the next versions. #skip-bdb # # * InnoDB # # InnoDB is enabled by default with a 10MB datafile in /var/lib/mysql/. # Read the manual for more InnoDB related options. There are many! innodb_buffer_pool_size = 2G # # * Security Features # # Read the manual, too, if you want chroot! # chroot = /var/lib/mysql/ # # If you want to enable SSL support (recommended) read the manual or my # HOWTO in /usr/share/doc/mysql-server/SSL-MINI-HOWTO.txt.gz # ssl-ca=/etc/mysql/cacert.pem # ssl-cert=/etc/mysql/server-cert.pem # ssl-key=/etc/mysql/server-key.pem [mysqldump] quick quote-names max_allowed_packet = 16M [mysql] #no-auto-rehash # faster start of mysql but no tab completition [isamchk] key_buffer = 16M
show status
SHOW STATUS; from 2007-09-24 at around 9am UK time.
mysql> show status; +-----------------------------------+--------------+ | Variable_name | Value | +-----------------------------------+--------------+ | Aborted_clients | 536 | | Aborted_connects | 3 | | Binlog_cache_disk_use | 2798 | | Binlog_cache_use | 11499278 | | Bytes_received | 128 | | Bytes_sent | 187 | | Com_admin_commands | 0 | | Com_alter_db | 0 | | Com_alter_table | 0 | | Com_analyze | 0 | | Com_backup_table | 0 | | Com_begin | 0 | | Com_change_db | 0 | | Com_change_master | 0 | | Com_check | 0 | | Com_checksum | 0 | | Com_commit | 0 | | Com_create_db | 0 | | Com_create_function | 0 | | Com_create_index | 0 | | Com_create_table | 0 | | Com_create_user | 0 | | Com_dealloc_sql | 0 | | Com_delete | 0 | | Com_delete_multi | 0 | | Com_do | 0 | | Com_drop_db | 0 | | Com_drop_function | 0 | | Com_drop_index | 0 | | Com_drop_table | 0 | | Com_drop_user | 0 | | Com_execute_sql | 0 | | Com_flush | 0 | | Com_grant | 0 | | Com_ha_close | 0 | | Com_ha_open | 0 | | Com_ha_read | 0 | | Com_help | 0 | | Com_insert | 0 | | Com_insert_select | 0 | | Com_kill | 0 | | Com_load | 0 | | Com_load_master_data | 0 | | Com_load_master_table | 0 | | Com_lock_tables | 0 | | Com_optimize | 0 | | Com_preload_keys | 0 | | Com_prepare_sql | 0 | | Com_purge | 0 | | Com_purge_before_date | 0 | | Com_rename_table | 0 | | Com_repair | 0 | | Com_replace | 0 | | Com_replace_select | 0 | | Com_reset | 0 | | Com_restore_table | 0 | | Com_revoke | 0 | | Com_revoke_all | 0 | | Com_rollback | 0 | | Com_savepoint | 0 | | Com_select | 1 | | Com_set_option | 0 | | Com_show_binlog_events | 0 | | Com_show_binlogs | 0 | | Com_show_charsets | 0 | | Com_show_collations | 0 | | Com_show_column_types | 0 | | Com_show_create_db | 0 | | Com_show_create_table | 0 | | Com_show_databases | 0 | | Com_show_errors | 0 | | Com_show_fields | 0 | | Com_show_grants | 0 | | Com_show_innodb_status | 0 | | Com_show_keys | 0 | | Com_show_logs | 0 | | Com_show_master_status | 0 | | Com_show_ndb_status | 0 | | Com_show_new_master | 0 | | Com_show_open_tables | 0 | | Com_show_privileges | 0 | | Com_show_processlist | 0 | | Com_show_slave_hosts | 0 | | Com_show_slave_status | 0 | | Com_show_status | 1 | | Com_show_storage_engines | 0 | | Com_show_tables | 0 | | Com_show_triggers | 0 | | Com_show_variables | 0 | | Com_show_warnings | 0 | | Com_slave_start | 0 | | Com_slave_stop | 0 | | Com_stmt_close | 0 | | Com_stmt_execute | 0 | | Com_stmt_fetch | 0 | | Com_stmt_prepare | 0 | | Com_stmt_reset | 0 | | Com_stmt_send_long_data | 0 | | Com_truncate | 0 | | Com_unlock_tables | 0 | | Com_update | 0 | | Com_update_multi | 0 | | Com_xa_commit | 0 | | Com_xa_end | 0 | | Com_xa_prepare | 0 | | Com_xa_recover | 0 | | Com_xa_rollback | 0 | | Com_xa_start | 0 | | Compression | OFF | | Connections | 4955 | | Created_tmp_disk_tables | 0 | | Created_tmp_files | 8876 | | Created_tmp_tables | 1 | | Delayed_errors | 0 | | Delayed_insert_threads | 0 | | Delayed_writes | 0 | | Flush_commands | 1 | | Handler_commit | 0 | | Handler_delete | 0 | | Handler_discover | 0 | | Handler_prepare | 0 | | Handler_read_first | 0 | | Handler_read_key | 0 | | Handler_read_next | 0 | | Handler_read_prev | 0 | | Handler_read_rnd | 0 | | Handler_read_rnd_next | 0 | | Handler_rollback | 0 | | Handler_savepoint | 0 | | Handler_savepoint_rollback | 0 | | Handler_update | 0 | | Handler_write | 131 | | Innodb_buffer_pool_pages_data | 119746 | | Innodb_buffer_pool_pages_dirty | 31 | | Innodb_buffer_pool_pages_flushed | 3638963 | | Innodb_buffer_pool_pages_free | 0 | | Innodb_buffer_pool_pages_latched | 0 | | Innodb_buffer_pool_pages_misc | 11326 | | Innodb_buffer_pool_pages_total | 131072 | | Innodb_buffer_pool_read_ahead_rnd | 464053 | | Innodb_buffer_pool_read_ahead_seq | 309544 | | Innodb_buffer_pool_read_requests | 13630172579 | | Innodb_buffer_pool_reads | 30353676 | | Innodb_buffer_pool_wait_free | 0 | | Innodb_buffer_pool_write_requests | 357681403 | | Innodb_data_fsyncs | 22827888 | | Innodb_data_pending_fsyncs | 0 | | Innodb_data_pending_reads | 0 | | Innodb_data_pending_writes | 0 | | Innodb_data_read | 956595687424 | | Innodb_data_reads | 36277030 | | Innodb_data_writes | 24783773 | | Innodb_data_written | 149630755328 | | Innodb_dblwr_pages_written | 3638963 | | Innodb_dblwr_writes | 71127 | | Innodb_log_waits | 11 | | Innodb_log_write_requests | 38330109 | | Innodb_log_writes | 22668941 | | Innodb_os_log_fsyncs | 22707853 | | Innodb_os_log_pending_fsyncs | 0 | | Innodb_os_log_pending_writes | 0 | | Innodb_os_log_written | 30367574016 | | Innodb_page_size | 16384 | | Innodb_pages_created | 880383 | | Innodb_pages_read | 58385838 | | Innodb_pages_written | 3638963 | | Innodb_row_lock_current_waits | 0 | | Innodb_row_lock_time | 1016013 | | Innodb_row_lock_time_avg | 10 | | Innodb_row_lock_time_max | 5133 | | Innodb_row_lock_waits | 94363 | | Innodb_rows_deleted | 1196230 | | Innodb_rows_inserted | 72018392 | | Innodb_rows_read | 6269505791 | | Innodb_rows_updated | 916464 | | Key_blocks_not_flushed | 0 | | Key_blocks_unused | 0 | | Key_blocks_used | 1714736 | | Key_read_requests | 4206978765 | | Key_reads | 3291069 | | Key_write_requests | 69792736 | | Key_writes | 65392073 | | Last_query_cost | 0.000000 | | Max_used_connections | 25 | | Ndb_cluster_node_id | 0 | | Ndb_config_from_host | | | Ndb_config_from_port | 0 | | Ndb_number_of_data_nodes | 0 | | Not_flushed_delayed_rows | 0 | | Open_files | 53 | | Open_streams | 0 | | Open_tables | 64 | | Opened_tables | 0 | | Prepared_stmt_count | 0 | | Qcache_free_blocks | 510 | | Qcache_free_memory | 38101336 | | Qcache_hits | 26164000 | | Qcache_inserts | 45278302 | | Qcache_lowmem_prunes | 194336 | | Qcache_not_cached | 10625745 | | Qcache_queries_in_cache | 1007 | | Qcache_total_blocks | 2575 | | Questions | 173008596 | | Rpl_status | NULL | | Select_full_join | 0 | | Select_full_range_join | 0 | | Select_range | 0 | | Select_range_check | 0 | | Select_scan | 1 | | Slave_open_temp_tables | 0 | | Slave_retried_transactions | 0 | | Slave_running | OFF | | Slow_launch_threads | 0 | | Slow_queries | 0 | | Sort_merge_passes | 0 | | Sort_range | 0 | | Sort_rows | 0 | | Sort_scan | 0 | | Ssl_accept_renegotiates | 0 | | Ssl_accepts | 0 | | Ssl_callback_cache_hits | 0 | | Ssl_cipher | | | Ssl_cipher_list | | | Ssl_client_connects | 0 | | Ssl_connect_renegotiates | 0 | | Ssl_ctx_verify_depth | 0 | | Ssl_ctx_verify_mode | 0 | | Ssl_default_timeout | 0 | | Ssl_finished_accepts | 0 | | Ssl_finished_connects | 0 | | Ssl_session_cache_hits | 0 | | Ssl_session_cache_misses | 0 | | Ssl_session_cache_mode | NONE | | Ssl_session_cache_overflows | 0 | | Ssl_session_cache_size | 0 | | Ssl_session_cache_timeouts | 0 | | Ssl_sessions_reused | 0 | | Ssl_used_session_cache_entries | 0 | | Ssl_verify_depth | 0 | | Ssl_verify_mode | 0 | | Ssl_version | | | Table_locks_immediate | 112841355 | | Table_locks_waited | 141664 | | Tc_log_max_pages_used | 0 | | Tc_log_page_size | 0 | | Tc_log_page_waits | 18 | | Threads_cached | 4 | | Threads_connected | 19 | | Threads_created | 53 | | Threads_running | 2 | | Uptime | 338650 | +-----------------------------------+--------------+ 251 rows in set (0.05 sec)
