From: Cary Cherng Date: November 17 2012 10:21am Subject: XA Transactions and number of Round Trips List-Archive: http://lists.mysql.com/mysql/228647 Message-Id: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary=e89a8f923b06367ec804ceae3ea8 --e89a8f923b06367ec804ceae3ea8 Content-Type: text/plain; charset=ISO-8859-1 I was reading about XA Transactions in the documentation http://dev.mysql.com/doc/refman/5.0/en/xa.html and near the end it says "The process for executing a global transaction uses two-phase commit (2PC). This takes place after the actions performed by the branches of the global transactions have been executed." Does this mean that two-phase commit incurs 3 round trips? One round trip for the branches of the global transaction to be sent, executed at their local site, and a response. A second round trip for the prepare phase message and response. A third round trip for the commit phase message and response. --e89a8f923b06367ec804ceae3ea8--