Settings for the Value Archive
[valarch] deleteNotArchivedFileSets
- Type
- bool
- Default
- 1
- Range
- 0|1
Specifies whether archive sets that have not already been backed up can be deleted.
- 0 = archive sets will not be deleted if they have not been backed up.
- 1 = archive sets will also be deleted when they have not been backed up.
[valarch] dispatchTimeout
- Type
- int
- Default
- 20
- Range
- Milliseconds
Use the config entry to specify the dispatch timeout in milliseconds. The shorter the
dispatchTimeout, the more CPU resources are required. This also increases the write
performance, meaning that more messages can be handled. The bigger the dispatchTimeout,
the less resources are required. Meaningfully use the entry for single or DuoCore
computers. Use short intervals only for multi-core processors.
For single core computers the timeout can be changed to, for example, 500
milliseconds.
[valarch] exclusiveReadThreadsForDM
- Type
- int
- Default
- 1
- Range
- 0..3
Defines how many threads handle the requests from the Data Manager favored. The sum of
the parameters exclusiveReadThreadsForDM and readThreadsPreferringOleDb may not be
higher than 3. If the total number of read threads is higher than 3, an error message is
displayed but however it is started.
[valarch] maxMemMappings
- Type
- short
- Default
- 30
- Range
- 15 .. 99 (wird nicht abgeprüft)
With this entry you can restrict the memory requirements. The smaller the value the
smaller is the data performance. The default is 15 MB. For big projects and with
sufficient virtual and real memory you can use a value up to 50 MB (possibly higher).
Note that a value archive requires memory also for other purposes than MemMappings
(above all buffer). Furthermore, the MemMappings are not "strictly" bound to this
setting and in a problem case, several mappings can be opened. Therefore, the use of
memory might be higher although you have limited it to a specific size.
[valarch] maxNumberOfFilesToBackup
- Type
- unsigned
- Default
- 5
- Range
- 3..25
Number of archive set files that will be backed up in one backup session. Is used to
avoid that the system is loaded too much when backup has been deactivated for a longer
time or is re-configured.
[valarch] maxNumberOfFilesToCompress
- Type
- short
- Default
- 5
- Range
- 3 .. 25
maxNumberOfFilesToCompress defines the maximum possible number of files per archive
allowed to be compressed in one procedure. Useful especially during the first use of the
compression for existing projects due to the undetermined number of archive records
available in this project.
[valarch] maxNumberOfFilesToDelete
- Type
- short
- Default
- 5
- Range
- 3 .. 25
Specifies how many archive sets should be deleted simultaneously. Use of the entry
avoids too high a CPU load.
[valarch] maxNumberOfOpenFileSets
- Type
- uint
- Default
- 100
- Range
- 10..500
Maximum number of archive sets that are open at the same time. If this limit is
exceeded, the open archive set with the lowest set number will be closed (this entry
only has performance reasons, if needed, the set will be opened again).
[valarch] maxNumberOfOpenFileSetsTolerance
- Type
- uint
- Default
- 10
- Range
- 0 .. 500
The system tries to reduce the number of open archive sets only when more files than the
maxNumberOfOpenFileSets + maxNumberOfOpenFileSetsTolerance are open. When the
maxNumberOfOpenFileSets = 100 and maxNumberOfOpenFileSetsTolerance = 10, the system
tries to reduce the number to maxNumberOfOpenFileSets (100) when the number of open
archive sets is 110.
[valarch] maxNumberOfReadThreads
- Type
- int
- Default
- 3
- Range
- 1..99
Number of threads that the Value Archive will start to perform simultaneous read
operations. Up to maxNumberOfReadThreads read requests can be answered parallel.
[valarch] maxReadQueueSize
- Type
- uint
- Default
- 128
The entry allows to define the maximum size of the read queue. The size is stated in
MB. When facing following error message within the log it is required to increase
the queue size:
WCCOAvalarch (<num>), <TIMESTAMP>, SYS, SEVERE, 0, , ManagerIF, Can't insert request to queue
[valarch] maxWaitForWrites
- Type
- int
- Default
- 0
- Range
- 0
When performing read operations for current values meaning reading values from WinCC OA
History database, the time taken could be quite long as concurrent read operations were
synchronized with the write operation. This means that the read operation was delayed
until all current values were written. To deactivate the synchronization, set the config
entry maxWaitForWrites in the valarch section to 0.
[valarch] mergeTimeList
- Type
- bool
- Default
- 0
- Range
- 0|1
When the config entry mergeTimeList = 1 (default 0 = behavior as hitherto), all archive
periods of a DPE are merged (when using history DB). This means that the DPE is
available in the archive from the first archiving until the end of last archiving (or
until 2.038 if it is archived at the moment).
[valarch] queryMaxValues
- Type
- ulong
- Default
- 100000
- Range
- >=0
Maximum number of return values for a single query. Entry 0 means no restriction.
[valarch] queryTimeout
- Type
- unsigned
- Default
- 0
- Range
- >=0
Maximum response time for a single query. Entry 0 means no restriction. The time is
specified in seconds.
[valarch] readThreadsPreferringOleDb
- Type
- int
- Default
- 1
- Range
- 0..3
Defines how many read threads handle the requests from OLE DB favored (when both DM and
OLE DB request at the same time). The sum of the parameters exclusiveReadThreadsForDM
and readThreadsPreferringOleDb may not be higher than 3. If the total number of read
threads is higher than 3, an error message is displayed but however it is started.
[valarch] refuseCNS
- Type
- bool
- Default
- 1
- Range
- 0|1
Specifies if a manager shall hold CNS data of the identification in memory. CNS data
is still tranferred with the identification but the manager discards this data.
[valarch] timeoutForBackup
- Type
- int
- Default
- 0
- Range
- >=0
Maximum timeout for a swap out (backup) in seconds. The swap out will be broken off
after this time. 0 = no timeout.
