Response Code 503 showing in application

[rijash (Rijash Patel)]

Hi,

Application is showing response Code "503" for RUM events ( (/intake/v2/rum/events) whenever we are seeing "Queue is Full" message in APM Server.

As per our understanding, If the server is not able to process the event it will be lost & not impact the application availability.

Could you please help to address the issue.

Elasticsearch version: 7.4.0

APM Server version: 7.4.0

APM Agent language and version: 1.9.0

Regards,
Rijash

[Hamidreza (Hamidreza Jahtalabziabari)]

Hi @rijash,

Thanks for reaching out.

The RUM agent sends the queued events to the APM server in a single requests and clears the queue regardless of whether APM server was able to process those events. Making a request to the APM server is the only way the agent can know if the server is able to process the request or not. This should not affect the availability of your application since these events are sent via a separate asynchronous http request.

Would you please explain a bit more, in what way the failing requests affect your application?

Cheers,
Hamid

[rijash (Rijash Patel)]

Hi Hamid,

Thank you for your prompt response here.

We are getting the below error log in in application server.

10.8.248.10 71.75.17.36, 10.8.248.10 - - [07/Feb/2020:18:24:05 -0500] "POST /intake/v2/rum/events HTTP/1.1" 503 568

Regards,
Rijash

[rijash (Rijash Patel)]

We are routing the RUM events captured for the application to APM server via nginx server.

[Hamidreza (Hamidreza Jahtalabziabari)]

The error log information is only there for your information. This error simply means that APM server (or Elasticsearch instance) can not handle the load and requires more resources. Since the APM components function independent from your application this shouldn't affect your application. However, it is recommended to either increase the resources on your servers or adjust the transactionSampleRate in the RUM agent configuration to avoid this error.