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## Table 23.64 Backup events 

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## 23.5.3.3 Using CLUSTERLOG STATISTICS in the NDB Cluster Management Client 

The NDB  management client’s CLUSTERLOG STATISTICS  command can provide a number of useful statistics in its output. Counters providing information about the state of the cluster are updated at 5- second reporting intervals by the transaction coordinator (TC) and the local query handler (LQH), and written to the cluster log. 

Transaction coordinator statistics.  Each transaction has one transaction coordinator, which is chosen by one of the following methods: 

•In a round-robin fashion 

•By communication proximity 

•By supplying a data placement hint when the transaction is started 

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## Note 

You can determine which TC selection method is used for transactions started from a given SQL node using the ndb_optimized_node_selection  system variable. 

All operations within the same transaction use the same transaction coordinator, which reports the following statistics: 

• Trans count.  This is the number transactions started in the last interval using this TC as the transaction coordinator. Any of these transactions may have committed, have been aborted, or remain uncommitted at the end of the reporting interval. 

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## Note 

Transactions do not migrate between TCs. 

• Commit count.  This is the number of transactions using this TC as the transaction coordinator that were committed in the last reporting interval. Because some transactions committed in this reporting 

