# High Availability API

> Please use the links below to view Reference Guide pages for the eXtremeDB High Availability API functions:

> mco_HA_async_send_data_to_replicas | Send transaction data from master buffer to replicas
> mco_HA_attach_master | Perform handshaking with the master, load the master’s current state (database), and wait to accept transactions from the master
> mco_HA_attach_replica | Wait for a connection request from a replica
> mco_HA_cancel | Instantly interrupt the replication processing
> mco_HA_commit_window | Force replicas to confirm a transaction package (window)
> mco_HA_create_cancel_socket | Create a cancel socket that can be used in the application
> mco_HA_destroy_cancel_socket | Close an explicitly created cancel socket
> mco_HA_detach_all_replicas | Detach (disconnect) all connected replicas
> mco_HA_detach_replica | Detach (disconnect) the replica identified by the channel pointer
> mco_HA_get_async_buf_info | Get information about usage of the asynchronous buffer
> mco_HA_enable_filter | Turn on/off partial replication
> mco_HA_get_channel_info | Get information about the I/O channel
> mco_HA_get_current_auto_oid | Get the current `auto_oid` value
> mco_HA_get_io_channel | Get the I/O channel of the replica referenced by the master database handle and the index of the replica
> mco_HA_get_ip_addr | Get the IP address associated with the specified I/O channel
> mco_HA_get_number_of_replicas | Get the count of replicas currently attached
> mco_HA_get_port | Get the port associated with the specified I/O channel
> mco_HA_get_mode | Get the MCO_HAMODE_* value specified for this database
> mco_HA_get_sequencer | Get the number of the "db version" (or "current-ness" in the sense of HA)
> mco_HA_keep_alive | Send the `KEEP_ALIVE` signal to replicas
> mco_HA_master_params_init | Initialize the master HA runtime parameters to default values
> mco_HA_replica_params_init | Initialize the replica HA runtime parameters to default values
> mco_HA_replica_stop | Cause a local asynchronous stop request to be sent from the standby application
> mco_HA_set_master_params | Set the master HA runtime parameters
> mco_HA_set_quorum | Set the HA quorum
> mco_HA_set_trans_window_size | Set the transaction packet (window) size
> mco_HA_start | Initialize the HA subsystem
> mco_HA_stop | Shutdown the HA subsystem
> mco_HA_trans_commit_synch | Implement synchronization of committed transactions completed by other (secondary) masters attached to a shared memory database