DatastoreSessionHandler too much contention on these datastore entities. please try again

[dmitriytestapic]

I use Datastore Session Handler and currently I'm getting an error:

Datastore upsert failed: {
  "error": {
    "code": 409,
    "message": "too much contention on these datastore entities. please try again.",
    "status": "ABORTED"
  }
}

t happens on page where are a few AJAX requests and they write data to the same Entity. How to fix that?

[jdpedrie]

Hi @dmitriytestapic,

This is a known drawback of the Datastore session handler. Take a look at the documentation for ways to mitigate these errors:

If you are building an ajax application which may issue multiple requests to the server, please design the session data carefully, in order to avoid possible data contentions. Also please see the 2nd example below for how to properly handle errors on write operations.

[dwsupplee]

@dmitriytestapic If there is anything else we can help out with, please feel free to re-open.