Use this space to discuss and ask questions about Exercise 2
ArcMaxCollect: This looks like can be used to limit amount of data retrieved by a single query. Keeping it lower will probably prevent sending large amount of data across the network or making system unresponsive for other users.
Archive_MaxQueryExecutionSec: Looks like it's limiting time a query can run. If it's kept too high, it can cause waiting on large queries and decrease amount of queries which can be run.
Thanks for your response! I would agree with your definition and use of both of these parameters. On the other side of things, you also may need to increase one or both of these parameters if you know you are running a particularly large query, however, this should be done with caution. In most situations, you would not want to raise these parameters as it could overwhelm the server if users are making large queries, as you mentioned. You can also absolutely lower these tuning parameters if you are notice that users are making too large of queries and it is effecting the server performance.
Thanks for the tips Danielle. Sounds like I shouldn't increase these parameters if users don't need to run large queries and don't decrease them if I don't observe performance issues.
Yes, that would be a great rule of thumb to follow! As a general rule, the default values of the tuning parameters are set to optimize performance - for the most part you won't want to change them unless you have a specific use case or notice a problem.
WHAT IS THE PURPOSE OF THIS TUNING PARAMETER?The ArcMaxCollect and Archive_MaxQueryExecutionSec parameters are used to limit amount of data and the number of threads for calls to the PI Archive from a single clientWHAT ARE THE DEFAULT?ArcMaxCollect : 150000 SecondsArchive_MaxQueryExecutionSec : 260 Number of EventsUNDER WHAT CONDITIONS DO YOU THINK YOU WOULD HAVE TO ALTER THE VALUES?When a "rogue consumer" or "heavy hitter" is performing "expensive queries" on the PI Server Leading to Performance Issues and there is need to Perform the Following:1) Limit the Amount of Data Processed as a result of this expensive queries2) Limit the Number of Thread for calls to the PI Archive from a single clientWHAT CONSIDERATIONS WOULD YOU HAVE IN RESETTING THIS?In the case of a persistent performance issue resulting from a rogue customer that meets the following:1) When I am unable to trace the rogue customer2) When Performance issue persist even after disconnecting the rogue customer
Thanks for your response! It looks like you have a good understanding of what these tuning parameters are used for and that is a perfect use case for changing these tuning parameters. As I mentioned above as well, on the opposite side of things, you may also need to increase these parameters if you know you are performing a large or expensive query, however, this should be done with caution, or only temporarily, as it can cause performance issues.
Retrieving data ...