Latency Keeps Building Up - Oracle Connection

[nabeelaslam1994]

Hello Team,

I am running a CDC task against an oracle database. The latency keeps building up and even after restarting the task, It starts building up again. Please guide on this. Last latency went upto 24 hours

Thanks,

Nabeel

[Zerxeus]

I am facing the similar issue, and I got the results from the query you have given.

My Source endpoint is Oracle with 8 threads parallel read on ASM.

[Dana_Baldwin]

Hi @Zerxeus 

We consider "good" read speed as 100 MB per second. Yours is varying between 26MB per second to 108 MB per second.

1. If reads are slow and redo / archived logs are read from ASM, try increasing number of concurrent ASM read threads. Default is one, max is 8. Seems you may already have maxed this out.

2. Try increasing internal parameter readAheadBlocks. Default value is 100000.

This is how many blocks we read at a time. Usually a block is 512 bytes, so default is to read 50 MB at a time. Requesting more could perform better on fast ASM.

3. Enable internal parameter asmUsePLSQLArray

This will use a different parallel ASM read option. I've seen this help at least one customer. It does not help in every situation, just have to try and see if it helps read speed.

4. Issue could be at the network level. One practical way to identify slow network issues is to take a relatively large file, 2GB for example (so it doesn't copy so fast you can't measure the rate) and measure the amount of time it takes to copy it from the source database server to the Replicate server. Present this to your network team.

5. One last thing is we almost always recommend having the Replicate server physically closer to the source than the target if you have to choose.

6. If these items do not help, and there is no error in the task log, we recommend working with our Professional Services team for help resolving the issue as it is not an issue/defect with the Qlik Replicate product itself. See this link and/or contact your Account Manager to engage them: How and when to contact Qlik's Professional Servic... - Qlik Community - 1714936

Thanks,

Dana