together, and share the same regional availability. A cell typically contains a set of tablets, a vtgate pool, and app servers that use the Vitess cluster. With Vitess, all components can be configured and brought 44 Features • Performance – Connection pooling - Multiplex front-end application queries onto a pool of MySQL connections to optimize perfor- mance. – Query de-duping – Reuse results of an in-flight connection pooling feature uses Go’s concurrency support to map these lightweight connections to a small pool of MySQL connections. As such, Vitess can easily handle thousands of connections. Poorly written

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 Other relevant pool-related variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . preload_buffer_size NotSupported rbr_exec_mode NotSupported sql_log_off NotSupported thread_pool_high_priority_connection NotSupported thread_pool_prio_kickup_timer NotSupported transaction_write_set_extraction NotSupported gets transformed into a reserved connection, a fresh, clean connections is returned to the connection pool to replace it. Once the vtgate session that initiated the reserved connections disconnects, all reserved

preload_buffer_size NotSupported rbr_exec_mode NotSupported sql_log_off NotSupported thread_pool_high_priority_connection NotSupported thread_pool_prio_kickup_timer NotSupported transaction_write_set_extraction NotSupported type of system variables. 45 Design VTTablet Reserve Pool VTTablet will have a new pool named reserved pool. Connections in the reserved pool are tied to a specific session and are closed when the session Reserve a connection, execute the set statements, move the reserve connection to active transaction pool and execute begin and the query. • ReserveRelease: This closes the reserved connection and also rollback

preload_buffer_size NotSupported rbr_exec_mode NotSupported sql_log_off NotSupported thread_pool_high_priority_connection NotSupported thread_pool_prio_kickup_timer NotSupported transaction_write_set_extraction NotSupported gets transformed into a reserved connection, a fresh, clean connections is returned to the connection pool to replace it. Once the vtgate session that initiated the reserved connections disconnects, all reserved this type of system variables. Design VTTablet Reserve Pool VTTablet will have a new pool named reserved pool. Connections in the reserved pool are tied to a specific session and are closed when the session

preload_buffer_size NotSupported rbr_exec_mode NotSupported sql_log_off NotSupported thread_pool_high_priority_connection NotSupported thread_pool_prio_kickup_timer NotSupported transaction_write_set_extraction NotSupported gets transformed into a reserved connection, a fresh, clean connections is returned to the connection pool to replace it. Once the vtgate session that initiated the reserved connections disconnects, all reserved this type of system variables. Design VTTablet Reserve Pool VTTablet will have a new pool named reserved pool. Connections in the reserved pool are tied to a specific session and are closed when the session

preload_buffer_size NotSupported rbr_exec_mode NotSupported sql_log_off NotSupported thread_pool_high_priority_connection NotSupported thread_pool_prio_kickup_timer NotSupported transaction_write_set_extraction NotSupported together, and share the same regional availability. A cell typically contains a set of tablets, a vtgate pool, and app servers that use the Vitess cluster. With Vitess, all components can be configured and brought 56 Features • Performance – Connection pooling - Multiplex front-end application queries onto a pool of MySQL connections to optimize perfor- mance. – Query de-duping – Reuse results of an in-flight

together, and share the same regional availability. A cell typically contains a set of tablets, a vtgate pool, and app servers that use the Vitess cluster. With Vitess, all components can be configured and brought needs. Features • Performance – Connection pooling - Multiplex front-end application queries onto a pool of MySQL connections to optimize perfor- mance. – Query de-duping – Reuse results of an in-flight connection pooling feature uses Go’s concurrency support to map these lightweight connections to a small pool of MySQL connections. As such, Vitess can easily handle thousands of connections. Poorly written

together, and share the same regional availability. A cell typically contains a set of tablets, a vtgate pool, and app servers that use the Vitess cluster. With Vitess, all components can be configured and brought needs. Features • Performance – Connection pooling - Multiplex front-end application queries onto a pool of MySQL connections to optimize perfor- mance. – Query de-duping – Reuse results of an in-flight connection pooling feature uses Go’s concurrency support to map these lightweight connections to a small pool of MySQL connections. As such, Vitess can easily handle thousands of connections. Poorly written

terminated by ‘\n’ from {.tableName} • write manifest & gzip Vitess RowCache • RowCache VS MySQL Buffer Pool • LRUCache • Base on binlog • DDL ? • key=prefix +body • every DDL —> prefix:=prefix+1 • lastest