Change Details

Philosophy: - Never perform "failovers" - No passive/unused hardware - No SPOF for service problems - All servers can be stopped at any time for maintenance - Replication channel is also not a SPOF - Independence from specific technologies/vendors ``` Master-Master active-passive replication with backup channel -------------------------------------- | ------------------ | | | | | v v v v master slave1 master slave1 (galera, GTID or eqiad <=> eqiad codfw <=> codfw binlog servers) |\ /| |\ /| | \ / | semisync | \ / | | X | replication | X | | / \ | | / \ | |/ \| |/ \| v v v v slave2 slave3 ... slave2 slave3 ... eqiad eqiad codfw codfw ```

Philosophy: - Never perform "failovers" - No passive/unused hardware - No SPOF for service problems - All servers can be stopped at any time for maintenance - Replication channel is also not a SPOF - Independence from specific technologies/vendors ``` Master-Master active-passive replication -> Regular replication or semisync with backup channel => Syncronous replication (maybe) --------------------------------------- *> Client connection | ------------------- | | | | | v v v v master [RO]slave1 [RO]master [RO]slave1 (galera, GTID or eqiad <=> eqiad codfw <=> codfw binlog servers) Application servers |\ /| |\ /| ------------------ | \ / | semisync | \ / | | Mediawiki | | X | replication | X | | * | | / \ | | / \ | | * | |/ \| |/ \| | v | v v v v | Proxy | slave2 slave3 ... slave2 slave3 ... <********************(syncronized | eqiad eqiad codfw codfw | fleet-wide) | ------------------ ```

Philosophy: - Never perform "failovers" - No passive/unused hardware - No SPOF for service problems - All servers can be stopped at any time for maintenance - Replication channel is also not a SPOF - Independence from specific technologies/vendors ``` Master-Master active-passive replication -> Regular replication or semisync with backup channel => Syncronous replication (maybe) -------------------------------------- - *> Client connection | ------------------- | | | | | v v v v master [RO]slave1 [RO]master [RO]slave1 (galera, GTID or eqiad <=> eqiad codfw <=> codfw binlog servers) Application servers |\ /| |\ /| ------------------ | \ / | semisync | \ / || | Mediawiki | | X | replication | X | | * | | / \ | | / \ || | * | |/ \| |/ \|| | v | v v v v | Proxy | slave2 slave3 ... slave2 slave3 ... <********************(syncronized | eqiad eqiad codfw codfw codfw codfw | fleet-wide) | ------------------ ```