there is possible data loss during fail over. Statement-Based Replication Middleware With statement-based replication middleware, a program intercepts every SQL query and sends it to one or all servers because SQL queries are broadcast (and not actual modified rows). If this is unacceptable, either the middleware or the application must query such values from a single server and then use those values in write (PRE- PARE TRANSACTION and COMMIT PREPARED) can be used to implement this in application code or middleware. 392 Chapter 24. High Availability and Load Balancing Asynchronous Multi-Master Replication

there is possible data loss during fail over. Statement-Based Replication Middleware With statement-based replication middleware, a program intercepts every SQL query and sends it to one or all servers because SQL queries are broadcast (and not actual modified rows). If this is unacceptable, either the middleware or the application must query such values from a single server and then use those values in write (PRE- PARE TRANSACTION and COMMIT PREPARED) can be used to implement this in application code or middleware. 392 Chapter 24. High Availability and Load Balancing Asynchronous Multi-Master Replication

wary of enforcing this timeout on connections made through connection-pooling software or other middleware, as such a layer may not react well to unexpected connection closure. It may be helpful to enable batches), there is possible data loss during fail over. SQL-Based Replication Middleware With SQL-based replication middleware, a program intercepts every SQL query and sends it to one or all servers. Each SQL queries are broadcast rather than actual data changes. If this is unacceptable, either the middleware or the application must determine such values from a single source and then use those values in

wary of enforcing this timeout on connections made through connection-pooling software or other middleware, as such a layer may not react well to unexpected connection closure. It may be helpful to enable batches), there is possible data loss during fail over. SQL-Based Replication Middleware With SQL-based replication middleware, a program intercepts every SQL query and sends it to one or all servers. Each SQL queries are broadcast rather than actual data changes. If this is unaccept- able, either the middleware or the application must determine such values from a single source and then use those values in

there is possible data loss during fail over. Statement-Based Replication Middleware With statement-based replication middleware, a program intercepts every SQL query and sends it to one or all servers SQL queries are broadcast (and not actual modified rows). If this is unaccept- able, either the middleware or the application must query such values from a single server and then use those values in write and are propagated to the standby servers via master-standby replication, not by the replication middleware. Care must also be taken that all transactions either commit or abort on all servers, perhaps using

there is possible data loss during fail over. Statement-Based Replication Middleware With statement-based replication middleware, a program intercepts every SQL query and sends it to one or all servers SQL queries are broadcast (and not actual modified rows). If this is unaccept- able, either the middleware or the application must query such values from a single server and then use those values in write and are propagated to the standby servers via master-standby replication, not by the replication middleware. Care must also be taken that all transactions either commit or abort on all servers, perhaps using

there is possible data loss during fail over. Statement-Based Replication Middleware With statement-based replication middleware, a program intercepts every SQL query and sends it to one or all servers because SQL queries are broadcast (and not actual modified rows). If this is unacceptable, either the middleware or the application must query such values from a single server and then use those values in write and are propagated to the standby servers via master-standby replication, not by the replication middleware. Care must also be taken that all transactions either commit or abort on all servers, perhaps using

there is possible data loss during fail over. Statement-Based Replication Middleware With statement-based replication middleware, a program intercepts every SQL query and sends it to one or all servers because SQL queries are broadcast (and not actual modified rows). If this is unacceptable, either the middleware or the application must query such values from a single server and then use those values in write and are propagated to the standby servers via master-standby replication, not by the replication middleware. Care must also be taken that all transactions either commit or abort on all servers, perhaps using

there is possible data loss during fail over. Statement-Based Replication Middleware With statement-based replication middleware, a program intercepts every SQL query and sends it to one or all servers because SQL queries are broadcast (and not actual modified rows). If this is unacceptable, either the middleware or the application must query such values from a single server and then use those values in write and are propagated to the standby servers via master-standby replication, not by the replication middleware. Care must also be taken that all transactions either commit or abort on all servers, perhaps using

there is possible data loss during fail over. Statement-Based Replication Middleware With statement-based replication middleware, a program intercepts every SQL query and sends it to one or all servers SQL queries are broadcast (and not actual modified rows). If this is unaccept- able, either the middleware or the application must query such values from a single server and then use those values in write and are propagated to the standby servers via master-standby replication, not by the replication middleware. Care must also be taken that all transactions either commit or abort on all servers, perhaps using