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strandafir
Contributor
Contributor

task run - cannot start error

Hello,

On a Replicate server with 8 vCPUs and 30 GB memory, we have created ~130 tasks that read from SQL Server and push to Kafka in AVRO format.

After starting the 105th task, we have bumped into this issue:cannot_start.jpg

 

The error does not appear in logs and it doesn't give any kind of details, except: "cannot start".

Is there any way to find the root problem?

 

Regards

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1 Solution

Accepted Solutions
john_wang
Support
Support

Hello @strandafir ,

If the given task is healthy, for example it can be run successfully if you stop others, then you are facing the Windows Heap Limitation. You can see the relevant description in Replicate User Guide the number of tasks that can be run on a single Replicate Server should not exceed 100 .

Please take note that there is no restrictions in Replicate code but some external OS level parameters can effect active task numbers. The good thing is you can easily increase the limit up to a certain amount, as described in Microsoft docs here: heap limitation , or desktop heap limits . However the mentioned Replicate Server is not powerful enough to run so many tasks in parallel even you modify the registry, out of memory errors or unexpected latency building up are expected, check Recommended hardware configuration for more information.  You may spread the tasks to multiple Replicate Servers, or re-config the single Replicate Server with more resources.

Hope this helps.

Regards,

John.

View solution in original post

1 Reply
john_wang
Support
Support

Hello @strandafir ,

If the given task is healthy, for example it can be run successfully if you stop others, then you are facing the Windows Heap Limitation. You can see the relevant description in Replicate User Guide the number of tasks that can be run on a single Replicate Server should not exceed 100 .

Please take note that there is no restrictions in Replicate code but some external OS level parameters can effect active task numbers. The good thing is you can easily increase the limit up to a certain amount, as described in Microsoft docs here: heap limitation , or desktop heap limits . However the mentioned Replicate Server is not powerful enough to run so many tasks in parallel even you modify the registry, out of memory errors or unexpected latency building up are expected, check Recommended hardware configuration for more information.  You may spread the tasks to multiple Replicate Servers, or re-config the single Replicate Server with more resources.

Hope this helps.

Regards,

John.