CODEWITHSUNDEEP
cluster-computingmarklogic
Harry
Harry

Reputation: 237

Marklogic latency : Document not found

I am working on a clustered marklogic environment where we have 10 Nodes. All nodes are shared E&D Nodes. Problem that we are facing: When a page is written in marklogic its takes some time (upto 3 secs) for all the nodes in the cluster to get updated & its during this time if I then do a read operation to fetch the previously written page, its not found.

Has anyone experienced this latency issue? and looked at eliminating it then please let me know.

Thanks

Upvotes: 0

Views: 129

Answers (1)

mblakele
mblakele

Reputation: 7840

It's normal for a new document to only appear after the database transaction commits. But it is not normal for a commit to take 3-sec.

  • Which version of MarkLogic Server?
  • Which OS and version?
  • Can you describe the hardware configuration?
  • How large are these documents? All other things equal, update time should be proportional to document size.

Can you reproduce this with a standalone host? That should eliminate cluster-related network latency from the transaction, which might tell you something. Possibly your cluster network has problems, or possibly one or more of the hosts has problems.

If you can reproduce the problem with a standalone host, use system monitoring to see what that host is doing at the time. On linux I favor something like iostat -Mxz 5 and top, but other tools can also help. The problem could be disk I/O - though it would have to be really slow to result in 3-sec commits. Or it might be that your servers are low on RAM, so they are paging during the commit phase.

If you can't reproduce it with a standalone host, then I think you'll have to run similar system monitoring on all the hosts in the cluster. That's harder, but for 10 hosts it is just barely manageable.

Upvotes: 2

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