Robert, What kind of performance degradation were you seeing here? I put together some simple flows to see if I could reproduce using 1.9.2 and current master. My flow consisted of GenerateFlowFile (generating 2 CSV rows per FlowFile) -> ConvertRecord (to Avro) -> MergeRecord (read Avro, write Avro) -> UpdateAttribute to try to mimic what you’ve got, given the details that I have.
I did see a performance degradation on the order of about 10%. So on my laptop I went from processing 2.49 MM FlowFiles in 1.9.2 in 5 mins to 2.25 MM on the master branch. Interestingly, I saw no real change when I enabled Snappy compression. For a point of reference, I also tried removing MergeRecord and just Generate -> Convert -> UpdateAttribute. I saw the same roughly 10% performance degradation. I’m curious if you’re seeing more than that. If so, I think a template would be helpful to understand what’s different. Thanks -Mark On Apr 24, 2020, at 4:50 PM, Robert R. Bruno <[email protected]<mailto:[email protected]>> wrote: Joe, In that part of the flow, we are using avro readers and writers. We are using snappy compression (which could be part of the problem). Since we are using avro at that point the embedded schema is being used by the reader and the writer is using the schema name property along with an internal schema registry in nifi. I can see what could potentially be shared. Thanks On Fri, Apr 24, 2020 at 4:41 PM Joe Witt <[email protected]<mailto:[email protected]>> wrote: Robert, Can you please detail the record readers and writers involved and how schemas are accessed? There can be very important performance related changes in the parsers/serializers of the given formats. And we've added a lot to make schema caching really capable but you have to opt into it. It is of course possible MergeRecord itself is the culprit for performance reduction but lets get a more full picture here. Are you able to share a template and sample data which we can use to replicate? Thanks On Fri, Apr 24, 2020 at 4:38 PM Robert R. Bruno <[email protected]<mailto:[email protected]>> wrote: I wanted to see if anyone else has experienced performance issues with the newest version of nifi and MergeRecord? We have been running on nifi 1.9.2 for awhile now, and recently upgraded to nifi 1.11.4. Once upgraded, our identical flows were no longer able to keep up with our data mainly at MergeRecord processors. We ended up downgrading back to nifi 1.9.2. Once we downgraded, all was keeping up again. There were no errors to speak of when we were running the flow with 1.11.4. We did see higher load on the OS, but this may have been caused by the fact there was such a tremendous backlog built up in the flow. Another side note, we saw one UpdateRecord processor producing errors when I tested the flow with nifi 1.11.4 with a small test flow. I was able to fix this issue by changing some parameters in my RecordWriter. So perhaps some underlying ways records are being handled since 1.9.2 caused the performance issue we saw? Any insight anyone has would be greatly appreciated, as we very much would like to upgrade to nifi 1.11.4. One thought was switching the MergeRecord processors to MergeContent since I've been told MergeContent seems to perform better, but not sure if this is actually true. We are using the pattern of chaining a few MergeRecord processors together to help with performance. Thanks in advance!
