4-6 Sun StorEdge 5310 NAS Troubleshooting Guide • December 2004
FIGURE4-3 Lost transaction handling on the Mirror
In the event an out-of-order transaction is received, the Master is notified and it re-
sends the missing transaction (Figure 4-3 on page 4-6). The out-of-order transaction -
TXID 4 in this example - is not committed until the missing transaction(s) is (are)
received and committed (TXID 3). This is crucial as there are many applications (e.g.,
databases) that require write ordering to be preserved.
Sun StorEdge 5310 NAS provides for handling of network or mirror link issues - e.g.,
loss of link, poor link quality-of-service etc. - through the use of an expanded journal
called the Mirror Log (Figure 4-4 on page4-7). The Mirror Log tracks write
transactions, serving as a repository for those transactions until they can be
committed to the Mirror system.