canceling statement coming in slave instance

Dear List,

In few of our Slave PostgreSQL machines.

I occasionally encounter below error.

While investigating online i came to know that this issue can be handled by below configuration parameters

"max_standby_archive_delay "

"max_standby_streaming_delay" 

I have increased the value of both the parameters as per below.

Original values:

"max_standby_archive_delay=30s"

"max_standby_streaming_delay=30s"

Current values:

"max_standby_archive_delay=30s" ----> was increased it to 300s but we did not get any benefit so we rollback it to original value

"max_standby_streaming_delay=300s"

But still i occasionally encounter the mention issue.

Please note that on Master node we have heavy write  operations and these Slave nodes are geographically distinct on a WAN connection.

Thanks in Advance

Rohit Arora