Revision as of 14:54, 8 September 2016 by Wiki admin
HA PostgreSQL stores the OVirt Engine configuration. It is configured with the following features:
- Fail-over of Master
- If Master breaks down, RA detects this fault and makes Master to stop, and Slave is promoted to new Master(promote).
- Switching between asynchronous and synchronous
- If Slave breaks down or LAN has some troubles, the transaction including Write operation will be stopped during the setting of synchronous replication. This means the stop of service. Therefore, RA switches dynamically from the synchronous to the asynchronous replication for prevented from stopping service.
- Automated discrimination of data old and new when initial starts
- When Pacemaker is started at the same time in the initial starts, RA compares the data of each node using "last xlog replay location" or "last receive replay location" to check which node has the newest data. The node which has the newest data will be Master.
su – postgres mkdir /var/lib/pgsql/pg_archive cd /var/lib/pgsql/data initdb
listen_addresses = '*' max_connections = 200 shared_buffers = 32MB wal_level = hot_standby synchronous_commit = on archive_mode = on archive_command = 'cp %p /var/lib/pgsql/pg_archive/%f' max_wal_senders = 5 wal_keep_segments = 32 replication_timeout = 9000 hot_standby = on max_standby_archive_delay = -1 max_standby_streaming_delay = -1 wal_receiver_status_interval = 2 hot_standby_feedback = on logging_collector = on log_filename = 'postgresql-%a.log' log_truncate_on_rotation = on log_rotation_age = 1d log_rotation_size = 0 log_timezone = 'Europe/Berlin' datestyle = 'iso, mdy' timezone = 'Europe/Berlin' lc_messages = 'en_US.UTF-8' lc_monetary = 'en_US.UTF-8' lc_numeric = 'en_US.UTF-8' lc_time = 'en_US.UTF-8' default_text_search_config = 'pg_catalog.english' restart_after_crash = off include '/var/lib/pgsql/tmp/rep_mode.conf'
Add permissions for PostgreSQL replication and database access over network by editing the
local all all trust host all all 127.0.0.1/32 trust host all all ::1/128 trust host all all 127.0.0.1/32 trust host all all OVIRTM/32 md5 host all all CLUSTERLAN_CLUSTER_N1_IP/32 trust host all all CLUSTERLAN_CLUSTER_N2_IP/32 trust host all all CLUSTERLAN_CLUSTER_IP/32 trust host replication all CLUSTERLAN_CLUSTER_N1_IP/32 trust host replication all CLUSTERLAN_CLUSTER_N2_IP/32 trust
su - postgres rm -rf /var/lib/pgsql/data/* pg_basebackup -hCLUSTERLAN_CLUSTER_N1_IP -Upostgres -D/var/lib/pgsql/data -Xstream -P mkdir /var/lib/pgsql/pg_archive
standby_mode = 'on' primary_conninfo = 'host=CLUSTERLAN_CLUSTER_N2_IP port=5432 user=postgres application_name=NODE2' restore_command = 'cp /var/lib/pgsql/pg_archive/%f %p' recovery_target_timeline = 'latest'
For further information see: clusterlabs