XA Transaction Recovery Process
There are two forms of XA transaction recovery, as follows:
Cold recovery. Cold recovery performed if the transaction manager process fails while a connection to an XA resource manager is open. When the transaction manager restarts, it reads the transaction manager log file and re-establishes the connection to the XA resource manager by calling xa_open_entry. It then initiates XA recover by calling xa_recover_entry.
Hot recovery. Hot recovery is performed if the transaction manager remains up while the connection between the transaction manager and the XA resource manager fails because the XA resource manager or the network fails. After the failure, the transaction manager periodically calls xa_open_entry to reconnect to the XA resource manager. When the connection is reestablished, the transaction manager initiates XA recovery by calling xa_recover_entry.