The Lock Diagnostics Write category provides summary information about database write lock usage. You can use this information when analyzing system performance.
For status information regarding locks in Geo SCADA Expert, see Locks. The Locks category displays all locks within the server, whereas database locks are specific to the 'database' and assist in identifying which operation is causing high lock utilization.
The database write locks are shown in rows, with each row representing a different lock. The status information shown for each lock is as follows:
- Lock Name—The Lock Name is the name of the lock in Geo SCADA Expert and indicates what or who has requested the lock.
- Lock Type—The Lock Type is either DB for the main database lock which protects all data, or Metadata which protects changes to the Metadata in Geo SCADA Expert
- Start Time—The Start Time is the time that the lock was first acquired. This is either from when Geo SCADA Expert was started, after a snapshot interval if the ResetCountersOnSnapshot log file setting is true, or after a manual reset in the Server Status tool.
- Last Access—Last Access is the last time that the lock was acquired.
- Write Locks—Write Locks is the total number of write locks, either from startup or since the lock diagnostics were last reset.
- Write Locks Per Second—Write Locks Per Second is the number of write locks per second as an average of the same period.
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Average Write Lock—The Average Write Lock is the average time spent in a write lock for the lock.
- Longest Write Lock—Longest Write Lock is the duration of longest write lock, either since start-up or since the lock diagnostics were last reset.
- Longest Write Lock Time— Longest Write Lock Time is the time stamp of longest write lock.
- Time in Write Lock—Time in Write Lock is the total time spent in write lock either since start-up or since the lock diagnostics were last reset. It is expressed as a percentage.
- Average Write Lock Wait—The Average Write Lock Wait is the average time to wait to acquire a write lock.
- Longest Write Lock Wait—Longest Write Lock Wait is the longest time to wait to acquire a write lock.
- Longest Write Lock Wait Time—The Longest Write Lock Wait Time is the time stamp of the longest time to wait to acquire a write lock.
You can access a context-sensitive menu by right-clicking on an entry in the list.
The options that are available are:
- Reset Lock Diagnostic—Select this option to reset the selected lock diagnostic.
- Reset All Lock Diagnostics—Select this option to reset all of the lock diagnostics.
- Enable Diagnostics—Select this option to enable Lock Diagnostics. The option is only available for use when the Lock Diagnostics are disabled. Locks per type are acquired.
- Disable Diagnostics—Select this option to disable all Lock Diagnostics. The comment 'Per-lock diagnostics disabled' replaces the list of locks.
These menu options apply to both database read and database write locks together. So, for example, the Reset Lock Diagnostics option will reset the write lock diagnostics and the read lock diagnostics.