Purpose
In the Frontend a local cache is used to speed up the load of files from SAP.
Example for an assembly with 264 components
- Load with empty cache: OmfDocOpenFast, duration: 22144 ms => 22 seconds
- Load with filled cache: OmfDocOpenFast, duration: 1920 ms => 2 seconds
Testdata from DSC Q18 (EHP6) client 100 with a fast local content server.
Overview
The local ECTR cache works very smoothly and automatically removes files that are no longer up-to-date or have not been accessed for a certain time. The more space ECTR can use on the local disk for this cache, the faster larger assemblies can be opened because the data is already there and doesn't have to be transferred over the network.
Disk space is nowadays no longer expensive. A 1TB SSD costs less than 100 EUR. Even if it only helps to save 20 seconds(which is very understated assumption, see example above for a one single open) a day, this means 20 seconds * 250 days = 5000 seconds = 83 minutes = around 1h23 saved in one year.
Besides that, there exist several possibilities to reduce the size of the local cache:
Automatic Cache Clean in background
5.2.2.0 - Cache clearing enabled to work automatic in background
There exists a feature which clears the local cache automatically in background.
Algorithm
- The access history of the cache-documents is considered and according to the pref "plm.clean.inodecache.timestamp.timediff.days" documents that have not been used for this time are determined. If these documents are in cache, they will be removed.
- All other documents from the cache are checked if they are still uptodate. The non-existent and non-up-to-date documents from the cache are deleted as well.
Configuration settings
default.txt
# Switch on automatic cache clear # true = The cache cleanup is triggered automatically 5 minutes after ECTR start # false = No automatic start of cache clear (default) plm.cache.uptodatecheck.clear = true # Eviction policy (Verdrängungsstrategie) # <value> = The files that have not been accessed fir this amount of days are deleted (default 30 days) plm.clean.inodecache.timestamp.timediff.days = 30 # Since 5.2.3.0: # Analogous to the cache cleanup, the cleanup of the inactive working directories can be triggered # Inactive working / session directories only exists if more then one working directory is used. See function "fnc.workdir.change" for details. # true = Switch on automatic cache clear for inactive session directories (default) # false = No automatic cache clear plm.inactive.sessions.autoClean = true # For manual working directory cleanup, the cleanup of the inactive working directories can be triggered # true = Clear inactive sessions as well when doing a manual clear for the active session # false = Don't touch inactive sessions when cleaning active session (default) plm.inactive.sessions.clear = false
Manual session clean
This function removes all read only and not modified files from active working directory.
If the plm.cache.uptodatecheck.clear set to true, then the cache is cleared too.
If the plm.inactive.sessions.clear set to true, then the inactive sessions are cleared too.
Check available disk space on start up
To avoid "out of space" situations, you can use this setting:
# Check available disk space on startup # true: Check available disk space # false: Don't check available disk space plm.control.check.freespace = true # Minimum required disk space in MB # Will only be used if "plm.control.check.freespace" is set to "true" plm.control.check.freespace.min.size = 50
On start, ECTR checks if the drive has less free space than specified in the preference plm.control.check.freespace.min.size. In this case, ECTR tries to free up space in stages.
At first, ECTR deletes all outdated files from cache, all files which have not been accessed for a long time from cache and from all inactive sessions.
- If there still not enough free space, then the files which have not been accessed for a long time removed from active session.
- If there still not enough free space, the cache is removed completely.
- If there still not enough free space, the inactive sessions are cleared from all read only and not modified files.
- If there still not enough free space, the active session is cleared from all read only and not modified files.