Pentaho Analysis - Mondrian

Concurrency issues on Mondrian 3.4 (trunk)

Details

  • Type: Bug Bug
  • Status: Closed Closed
  • Priority: Blocker Blocker
  • Resolution: Fixed
  • Affects Version/s: 3.4.1 GA (4.5.0 GA Suite Release), 3.4.3 GA
  • Fix Version/s: 3.4.4 GA
  • Component/s: None
  • Labels:
    None
  • CS:
    CS1
  • Customer Case:
  • QA Validation Status:
    Not Yet Validated

Description

Apparently, Mondrian is issuing only one mdx query at a time.

Steps to reproduce:

Open Analysis View - Create connection over steel-wheels and issue a top count query. We have a breakpoint set in RolapNativeTopCount so execution stops there.

Open another analysis View - Create connection over SampleData (another cube which should rule out cache sharing, I guess) .
Mondrian is called to get that first screen, execution goes into RolapConnection.execute, shepherdExecution method is called but the executeInternal (line 628) is not called - only after execution is resumed on the previous breakpoint.

Apparently, if I wait long enough (about 4 minutes), the second thread will go into executeInternal due to a new request coming in from JPivot.

Issue Links

is duplicated by

Bug - A problem which impairs or prevents the functions of the product. MONDRIAN-1165 Parallel mdx queries

  • Unknown - Priority Unknown or Unassigned
  • Closed - The issue is considered finished, the resolution is correct. Issues which are not closed can be reopened.

Activity

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Pedro Vale added a comment -
Attached screenshot with callstack in netbeans
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Pedro Vale added a comment - Attached screenshot with callstack in netbeans
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Pedro Vale added a comment -
RolapConnection.executeInternal is not called in parallel.
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Pedro Vale added a comment - RolapConnection.executeInternal is not called in parallel.
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Alex added a comment - - edited
Can please someone take a look into this as a matter of urgency?
Our clients are complaining about performance issues with the application.


thank you,
Alex
Flixmedia LTD
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Alex added a comment - - edited Can please someone take a look into this as a matter of urgency? Our clients are complaining about performance issues with the application. thank you, Alex Flixmedia LTD
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Will Gorman added a comment -
Hi Luc, please investigate this. Thanks!

Will
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Will Gorman added a comment - Hi Luc, please investigate this. Thanks! Will
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Luc Boudreau added a comment -
Fixed in master and lagunitas branches. See https://github.com/pentaho/mondrian/commit/ccfc09ca73530ff5ab3dd52ed1abd00a1c229753

If this needs to b e backported to a specific version, file a CUST case in jira and let me know which.

QA: This issue is pretty hard to reproduce. I have created a unit test which runs two queries simultaneously and makes sure that they can be both evaluated in parallel. ( mondrian.test.BasicQueryTest.testConcurrentStatementRun_2() ) One possible way to test this on the BI server would be to run two reports at the same time. Make sure they don't contain the same columns or else you will pull the data from the cache instead of running completely concurrently. What you expect is for two reports to be generated at once. Notice I'm not even sure this is actually possible, since I don't know how Analyzer's servlet operates internally. It might not support rendering two reports at once for all I know.
Show
Luc Boudreau added a comment - Fixed in master and lagunitas branches. See https://github.com/pentaho/mondrian/commit/ccfc09ca73530ff5ab3dd52ed1abd00a1c229753 If this needs to b e backported to a specific version, file a CUST case in jira and let me know which. QA: This issue is pretty hard to reproduce. I have created a unit test which runs two queries simultaneously and makes sure that they can be both evaluated in parallel. ( mondrian.test.BasicQueryTest.testConcurrentStatementRun_2() ) One possible way to test this on the BI server would be to run two reports at the same time. Make sure they don't contain the same columns or else you will pull the data from the cache instead of running completely concurrently. What you expect is for two reports to be generated at once. Notice I'm not even sure this is actually possible, since I don't know how Analyzer's servlet operates internally. It might not support rendering two reports at once for all I know.
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Pedro Alves added a comment -
Luc, you're amazing.

Forget qa . Validated! My dashboard went from over one minute to 13 seconds!
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Pedro Alves added a comment - Luc, you're amazing. Forget qa . Validated! My dashboard went from over one minute to 13 seconds!
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Luc Boudreau added a comment - - edited
Let's not be too hasty. :) We have other customers waiting on this fix. Triage, it is up to you folks.
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Luc Boudreau added a comment - - edited Let's not be too hasty. :) We have other customers waiting on this fix. Triage, it is up to you folks.
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Will Gorman added a comment -
Hi Luc, please backport this to the latest 3.4.x codeline so we can create a Mondrian 3.4.4 patch release.

Thanks!

Will
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Will Gorman added a comment - Hi Luc, please backport this to the latest 3.4.x codeline so we can create a Mondrian 3.4.4 patch release. Thanks! Will
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Luc Boudreau added a comment -
I've created a branch called 3.4.4 and backported everything. The correct build properties are also set. It is ready to be built.
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Luc Boudreau added a comment - I've created a branch called 3.4.4 and backported everything. The correct build properties are also set. It is ready to be built.
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Kurtis Cruzada added a comment -
Updated Status from in Progress to Resolved.
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Kurtis Cruzada added a comment - Updated Status from in Progress to Resolved.
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Brandon Bruce added a comment -
This is hard to prove but did the following:
*I upgraded to 3.4.4 mondrian
*opened two different reports with different data sources in two different windows
*cleared the cache
*reran the reports at (roughly) the same time. The reports appear to run in parallel.
Show
Brandon Bruce added a comment - This is hard to prove but did the following: *I upgraded to 3.4.4 mondrian *opened two different reports with different data sources in two different windows *cleared the cache *reran the reports at (roughly) the same time. The reports appear to run in parallel.
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Brandon Bruce added a comment -
assigning back to Larry for release
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Brandon Bruce added a comment - assigning back to Larry for release

People

  • Assignee:
    Larry Grill
    Reporter:
    Pedro Vale
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Dates

  • Created:
    Updated:
    Resolved: