For TMemFiles, Write() file onOpen to register with server and avoid relying...

For TMemFiles, Write() file onOpen() to register with server and avoid relying on first flush for event data. This should fix problems with (Run2 style) Derivation, where only few events get written causing sequencing issues with event and metadata.

requested review from @amete and @mnowak

Tag @amete , @mnowak ,

This should fix the sequencing issues we see in short derivation jobs. If a worker writes fewer events than the autoflush setting, then the first data is flushed on finalize, which is when the worker TMemFile is connected to the merger. But the writer is terminated after all metadata is written, which happens on metadata stop, ie before the last event data.

This change calls Write() on file creation (onOpen()), registering the TMemFile with the merger and causing it to wait until event data writing is complete. @amete is always great for some independent testing and since it touches APR code, @mnowak needs to OK the change.

Thanks, Peter

approved this merge request

Hi Peter. As long as it does what you need I don't see anything wrong here!
Cheers, Marcin

approved this merge request

Thanks a lot @gemmeren. This looks good and fixes the issue in my local test as well. Given Marcin's OK, too, let me mark this as ready.

marked this merge request as ready

This merge request affects 1 package:

• Database/APR/RootStorageSvc

This merge request affects 1 file:

• Database/APR/RootStorageSvc/src/RootDatabase.cpp

Adding @mnowak ,@ssnyder as watchers

added Database master review-pending-level-1 labels

CI Result FAILURE (hash 6e40c704)

	Athena	AthSimulation	AthGeneration	AthAnalysis
externals
cmake
make
tests

Full details available on this CI monitor view. Check the JIRA CI status board for known problems
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
AthGeneration: number of compilation errors 0, warnings 0
AthAnalysis: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 62626]

Jenkins please retry a build

This merge request affects 1 package:

• Database/APR/RootStorageSvc

This merge request affects 1 file:

• Database/APR/RootStorageSvc/src/RootDatabase.cpp

Adding @mnowak ,@ssnyder as watchers

CI Result FAILURE (hash 6e40c704)

	Athena	AthSimulation	AthGeneration	AthAnalysis
externals
cmake
make
tests

Full details available on this CI monitor view. Check the JIRA CI status board for known problems
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
AthGeneration: number of compilation errors 0, warnings 0
AthAnalysis: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 62657]

The CI failure is unrelated, see ATLASRECTS-7384.

Jenkins please retry a build

Build area was cleaned as per request posted in the DB. The full software build will be performed

This merge request affects 1 package:

• Database/APR/RootStorageSvc

This merge request affects 1 file:

• Database/APR/RootStorageSvc/src/RootDatabase.cpp

Adding @mnowak ,@ssnyder as watchers

CI Result FAILURE

	Athena	AthSimulation	AthGeneration	AthAnalysis
externals
cmake	N/A	N/A	N/A	N/A
make	N/A	N/A	N/A	N/A
tests	N/A	N/A	N/A	N/A

Due to problems in externals build or cmake configuration the job is stopped, results are not available on the ATLAS CI monitor
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
AthGeneration: number of compilation errors 0, warnings 0
AthAnalysis: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 62763]

Jenkins please retry a build

This merge request affects 1 package:

• Database/APR/RootStorageSvc

This merge request affects 1 file:

• Database/APR/RootStorageSvc/src/RootDatabase.cpp

Adding @mnowak ,@ssnyder as watchers

CI Result SUCCESS (hash 6e40c704)

	Athena	AthSimulation	AthGeneration	AthAnalysis
externals
cmake
make
tests

Full details available on this CI monitor view. Check the JIRA CI status board for known problems
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
AthGeneration: number of compilation errors 0, warnings 0
AthAnalysis: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 62794]

added review-approved label and removed review-pending-level-1 label

merged

mentioned in commit 50077943

added sweep:ignore label

mentioned in merge request !59267 (merged)

mentioned in commit f3ace271