Troubleshooting connection timeouts

You can use the Dgraph --net-timeout flag to help prevent timeout issues during data ingest operations.

The MDEX Engine has a default request timeout of 30 seconds. This setting determines the maximum number of seconds that the MDEX Engine waits for the client to download data from queries across the network. The client can be an end user sending a query to the MDEX Engine or, for data ingest operations, an ETL client program that is loading records into the engine.

If the client opens a connection with the MDEX Engine, the engine will wait (for the length of the timeout period) for the receipt of client data on that socket. If the client does not send data within the timeout limit, then the MDEX Engine will drop the connection and log an HTTP 408 error in the Dgraph log.

For ingest operations, this timeout limit may pose problems if you have a DIWS client that takes longer to send data. If the timeout limit is exceeded, the ingest request fails (because the MDEX Engine closes the connection) and the record batch is not loaded into the MDEX Engine.

If you continually see HTTP 408 errors in the logs, first verify that your ETL client is working properly. For example, make sure that the program is not spending an unusual amount of time in an operation that would cause it to exceed the timeout limit.

If you believe that the ETL client is executing as expected but needs a longer request timeout period, then you can try increasing the MDEX Engine's request timeout setting. Use the Dgraph --net-timeout flag to set the request timeout to a number that works for the ETL client. You will probably have to experiment with several settings to find the one that is optimal for your needs.