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Status Declined
Categories Data Archive
Created by Guest
Created on Aug 20, 2022

PI Data Archive: Improve piarchss performance

PI Archive Subsystem should be able to use operating memory more efficiently. For example by loading as many non-primary archives into its process memory as possible (perhaps it could be affected by a user setting).
  • ADMIN RESPONSE
    Aug 20, 2022
    In a multi-user environment, our testing has shown that while there is some room for improvement on the Data Archive read cache, the Windows file system cache does a pretty good job. In our conversation with customers, there are very few that would want to manually prioritize what gets loaded into memory as that usually only optimize one operation or use case but reality is that the great majority of Data Archive installations are for multiple users each with their own needs and use case. With that in mind, the effort does not justify the benefit for all our customers across the board. As such, we have no plans to implement this idea.
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  • Guest
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    Aug 20, 2022
    I'd like to add something here. I'd like to see where I could force certain archives into memory. While I agree that the archive ss does manage the memory along with the file system cache, there is no way to override it given the use of the system. Ideally, a certain portion of memory would be reserved to say keep the last x days archives in memory. But right now, that is not forced. So if I have users doing very large searches, they end up dumping some of the last x days out of memory. I should be able to pick archives that are memory resident depending upon what my users are doing (e.g. I always want to make sure that the last x days are loaded into memory so that my analysis server and users have the quickest response, or maybe a user is doing a study over a time period and wants those in memory during pull of the analysis). Currently there is no way to force the caching based upon business requirements.
  • Guest
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    Aug 20, 2022
    The windows file system cache currently take files off of memory if it's less used. When system has very large memory(>100GB), in some cases, Windows will voluntarilly free memory as some archives are less used. This is not efficient for the occasional analytic purpose long term queries. It would be nice to be able to set "keep at least x months of data in cache"