ExecuteGet do not return the updated value from couchbase server


We use couchbase server 2.2.0 in our production application.

In the last couple of month , when we ExecuteGet on a value, we get the previous value instead of the updated one.

Example scenario (all the actions are synchronized):
UserBalance_12345 is 500.

  1. ExecuteSet(“UserBalance_12345”,1000)
  2. ExecuteGet(“UserBalance_12345”); -> The result is 500 instead of 1000.

This scenario occur very rarely but still happen and make damage to us because people say their balance is not updated immidietly.

How can such a scenario happen in couchbase?
Do you have a solution for this scenario?