Joe I dont recall the specific version in which we got it truly sorted but there was an issue with our default settings for an important content repo property and how we handled mixture of large/small flowfiles written within the same underlying slab/claim in the content repository.
Please check what you have for conf/nifi.properties nifi.content.claim.max.appendable.size= What value do you have there? I recommend reducing it to 50KB and restarting. Can you show your full 'nifi.content' section from the nifi.properties? Thanks On Wed, Jul 12, 2023 at 7:54 AM Joe Obernberger < joseph.obernber...@gmail.com> wrote: > Raising this thread from the dead... > Having issues with IO to the flowfile repository. NiFi will show 500k > flow files and a size of ~1.7G - but the size on disk on each of the 4 > nodes is massive - over 100G, and disk IO to the flowfile spindle is just > pegged doing writes. > > I do have ExtractText processors that take the flowfile content (.*) and > put it into an attribute, but the sizes of these is maybe in the 10k at > most size. How can I find out what module (there are some 2200) is causing > the issue? I think I'm doing something fundamentally wrong with NiFi. :) > Perhaps I should change the size of all the queues to something less than > 10k/1G? > > Under cluster/FLOWFILE STORAGE, one of the nodes shows 3.74TBytes of > usage, but it's actually ~150G on disk. The other nodes are correct. > > Ideas on what to debug? > Thank you! > > -Joe (NiFi 1.18) > On 3/22/2023 12:49 PM, Mark Payne wrote: > > OK. So changing the checkpoint internal to 300 seconds might help reduce > IO a bit. But it will cause the repo to become much larger, and it will > take much longer to startup whenever you restart NiFi. > > The variance in size between nodes is likely due to how recently it’s > checkpointed. If it stays large like 31 GB while the other stay small, that > would be interesting to know. > > Thanks > -Mark > > > On Mar 22, 2023, at 12:45 PM, Joe Obernberger > <joseph.obernber...@gmail.com> <joseph.obernber...@gmail.com> wrote: > > Thanks for this Mark. I'm not seeing any large attributes at the moment > but will go through this and verify - but I did have one queue that was set > to 100k instead of 10k. > I set the nifi.cluster.node.connection.timeout to 30 seconds (up from 5) > and the nifi.flowfile.repository.checkpoint.interval to 300 seconds (up > from 20). > > While it's running the size of the flowfile repo varies (wildly?) on each > of the nodes from 1.5G to over 30G. Disk IO is still very high, but it's > running now and I can use the UI. Interestingly at this point the UI shows > 677k files and 1.5G of flow. But disk usage on the flowfile repo is 31G, > 3.7G, and 2.6G on the 3 nodes. I'd love to throw some SSDs at this > problem. I can add more nifi nodes. > > -Joe > On 3/22/2023 11:08 AM, Mark Payne wrote: > > Joe, > > The errors noted are indicating that NiFi cannot communicate with > registry. Either the registry is offline, NiFi’s Registry Client is not > configured properly, there’s a firewall in the way, etc. > > A FlowFile repo of 35 GB is rather huge. This would imply one of 3 things: > - You have a huge number of FlowFiles (doesn’t seem to be the case) > - FlowFiles have a huge number of attributes > or > - FlowFiles have 1 or more huge attribute values. > > Typically, FlowFile attribute should be kept minimal and should never > contain chunks of contents from the FlowFile content. Often when we see > this type of behavior it’s due to using something like ExtractText or > EvaluateJsonPath to put large blocks of content into attributes. > > And in this case, setting Backpressure Threshold above 10,000 is even more > concerning, as it means even greater disk I/O. > > Thanks > -Mark > > > On Mar 22, 2023, at 11:01 AM, Joe Obernberger > <joseph.obernber...@gmail.com> <joseph.obernber...@gmail.com> wrote: > > Thank you Mark. These are SATA drives - but there's no way for the > flowfile repo to be on multiple spindles. It's not huge - maybe 35G per > node. > I do see a lot of messages like this in the log: > > 2023-03-22 10:52:13,960 ERROR [Timer-Driven Process Thread-62] > o.a.nifi.groups.StandardProcessGroup Failed to synchronize > StandardProcessGroup[identifier=861d3b27-aace-186d-bbb7-870c6fa65243,name=TIKA > Handle Extract Metadata] with Flow Registry because could not retrieve > version 1 of flow with identifier d64e72b5-16ea-4a87-af09-72c5bbcd82bf in > bucket 736a8f4b-19be-4c01-b2c3-901d9538c5ef due to: Connection refused > (Connection refused) > 2023-03-22 10:52:13,960 ERROR [Timer-Driven Process Thread-62] > o.a.nifi.groups.StandardProcessGroup Failed to synchronize > StandardProcessGroup[identifier=bcc23c03-49ef-1e41-83cb-83f22630466d,name=WriteDB] > with Flow Registry because could not retrieve version 2 of flow with > identifier ff197063-af31-45df-9401-e9f8ba2e4b2b in bucket > 736a8f4b-19be-4c01-b2c3-901d9538c5ef due to: Connection refused (Connection > refused) > 2023-03-22 10:52:13,960 ERROR [Timer-Driven Process Thread-62] > o.a.nifi.groups.StandardProcessGroup Failed to synchronize > StandardProcessGroup[identifier=bc913ff1-06b1-1b76-a548-7525a836560a,name=TIKA > Handle Extract Metadata] with Flow Registry because could not retrieve > version 1 of flow with identifier d64e72b5-16ea-4a87-af09-72c5bbcd82bf in > bucket 736a8f4b-19be-4c01-b2c3-901d9538c5ef due to: Connection refused > (Connection refused) > 2023-03-22 10:52:13,960 ERROR [Timer-Driven Process Thread-62] > o.a.nifi.groups.StandardProcessGroup Failed to synchronize > StandardProcessGroup[identifier=920c3600-2954-1c8e-b121-6d7d3d393de6,name=Save > Binary Data] with Flow Registry because could not retrieve version 1 of > flow with identifier 7a8c82be-1707-4e7d-a5e7-bb3825e0a38f in bucket > 736a8f4b-19be-4c01-b2c3-901d9538c5ef due to: Connection refused (Connection > refused) > > A clue? > > -joe > On 3/22/2023 10:49 AM, Mark Payne wrote: > > Joe, > > 1.8 million FlowFiles is not a concern. But when you say “Should I reduce > the queue sizes?” it makes me wonder if they’re all in a single queue? > Generally, you should leave the backpressure threshold at the default > 10,000 FlowFile max. Increasing this can lead to huge amounts of swapping, > which will drastically reduce performance and increase disk utilization > very significantly. > > Also from the diagnostics, it looks like you’ve got a lot of CPU cores, > but you’re not using much. And based on the amount of disk space available > and the fact that you’re seeing 100% utilization, I’m wondering if you’re > using spinning disks, rather than SSDs? I would highly recommend always > running NiFi with ssd/nvme drives. Absent that, if you have multiple disk > drives, you could also configure the content repository to span multiple > disks, in order to spread that load. > > Thanks > -Mark > > On Mar 22, 2023, at 10:41 AM, Joe Obernberger > <joseph.obernber...@gmail.com> <joseph.obernber...@gmail.com> wrote: > > Thank you. Was able to get in. > Currently there are 1.8 million flow files and 3.2G. Is this too much for > a 3 node cluster with mutliple spindles each (SATA drives)? > Should I reduce the queue sizes? > > -Joe > On 3/22/2023 10:23 AM, Phillip Lord wrote: > > Joe, > > If you need the UI to come back up, try setting the autoresume setting in > nifi.properties to false and restart node(s). > This will bring up every component/controllerService up stopped/disabled > and may provide some breathing room for the UI to become available again. > > Phil > On Mar 22, 2023 at 10:20 AM -0400, Joe Obernberger > <joseph.obernber...@gmail.com> <joseph.obernber...@gmail.com>, wrote: > > atop shows the disk as being all red with IO - 100% utilization. There > are a lot of flowfiles currently trying to run through, but I can't > monitor it because....UI wont' load. > > -Joe > > On 3/22/2023 10:16 AM, Mark Payne wrote: > > Joe, > > I’d recommend taking a look at garbage collection. It is far more likely > the culprit than disk I/O. > > Thanks > -Mark > > On Mar 22, 2023, at 10:12 AM, Joe Obernberger > <joseph.obernber...@gmail.com> <joseph.obernber...@gmail.com> wrote: > > I'm getting "java.net.SocketTimeoutException: timeout" from the user > interface of NiFi when load is heavy. This is 1.18.0 running on a 3 node > cluster. Disk IO is high and when that happens, I can't get into the UI to > stop any of the processors. > Any ideas? > > I have put the flowfile repository and content repository on different > disks on the 3 nodes, but disk usage is still so high that I can't get in. > Thank you! > > -Joe > > > -- > This email has been checked for viruses by AVG antivirus software. > www.avg.com > > > > <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> > Virus-free.www.avg.com > <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> > > > > >
