Performance: export after nsrlsvr analysis very slow

[joachimmetz]

While running:

psort.py --analysis nsrlsvr --nsrlsvr-hash md5 --nsrlsvr-host 127.0.0.1 --nsrlsvr-port 9120 -w output.log --disable-zeromq test.plaso 

The export after the analysis is very slow, a couple of events per update cycle.

To do:

• set up end-to-end test - Add end-to-end test for nsrlsvr #1904
• find and fix issue

[pettai]

+1
I've noticed this too. Same if you run a second psort run with another analysis plugin, eg. tagging

[kinky-it]

The slow export speed after running nsrlsvr analysis is caused by the fact that (in plaso 1.5.1), the zip file with tags is opened for each retrieval of a tag (zip_file.py#L1826). For dump files with large sets of tags (typically, after running the nsrlsvr analysis plugin), this causes the zip file to be opened thousands of times.

Even if the zip file with tags would be kept open, the lack of seek support in the zip stream would cause similar troubles. It would cause the zip to be reopened every time that the tag offset in the index is non-sequential. Reading the zip file just once and keeping it open as a memfile fixes the problems, and speeds up the export tremendously.

Not sure, and have not checked thoroughly, but it seems that this is fixed in master already.

[Onager]

Not making September release, removing milestone.