MySQL error 1161 (ER_NET_WRITE_INTERRUPTED) means the server timed out while trying to send data to the client, usually due to network latency, slow clients, or low timeout settings.
MySQL Error 1161: ER_NET_WRITE_INTERRUPTED signals that the server hit its net_write_timeout limit while writing packets to the client. Increase net_write_timeout, optimize long-running queries, and check network stability to resolve the issue.
Got timeout writing communication packets
Error 1161 appears with the message "Got timeout writing communication packets" when MySQL cannot finish sending data to the client within the configured net_write_timeout period. The server closes the connection, returning SQLSTATE 08S01 and leaving the client with incomplete results.
The condition is classified as a connection error because it arises during data transmission over the TCP link between server and client.
Addressing it quickly prevents partial data delivery, client crashes, and stalled application threads.
Network latency or packet loss slows down the TCP stream, making the server exceed net_write_timeout (default 60 seconds). High-latency links, VPN tunnels, or overloaded network hardware frequently trigger the issue.
Slow client consumption also causes timeouts. If the client reads rows very slowly, the server's send buffer fills and the write call blocks until the timeout fires.
Large result sets intensify the problem.
Queries that stream millions of rows force prolonged writes, magnifying the chance of hitting the timeout.
First, raise net_write_timeout and optionally net_read_timeout to give the server more time. Persistent issues require optimizing long-running queries and reducing result-set size.
Validate network health with ping and traceroute.
Repair faulty cables, upgrade bandwidth, or move the client closer to the database to remove latency hotspots.
Batch export jobs that SELECT huge tables often fail mid-stream. Paginate results with LIMIT ... OFFSET or use INTO OUTFILE so MySQL writes directly to disk, avoiding the client pipe.
Long-running analytical queries on BI tools can time out.
Tune indexes, add WHERE filters, or create summary tables to shorten execution and transmission time.
Monitor Connections_aborted on the server to catch early spikes in network timeouts.
Alert the ops team before applications feel impact.
Keep net_write_timeout slightly above the longest expected client read gap, but below TCP keepalive to avoid ghost sessions.
Leverage Galaxy's lightning-fast SQL editor to prototype filtered queries and preview result size, reducing the risk of pulling massive unneeded datasets into production apps.
Error 2013 (Lost connection to MySQL server during query) fires when the server drops the link for any reason, not just write timeouts.
Similar fixes apply: tune timeouts and stabilize the network.
Error 2006 (MySQL server has gone away) indicates the server closed the socket, often due to max_allowed_packet overflow or inactivity timeouts. Increase max_allowed_packet and check wait_timeout.
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No, the variable cannot be disabled. Setting it extremely high (for example 7200 seconds) mimics disabling but risks hanging connections indefinitely.
Raising the timeout has negligible CPU cost but may tie up idle connections longer if clients disappear. Monitor Threads_connected to avoid exhaustion.
Production datasets are larger and networks more complex, increasing latency and result-set sizes beyond what local testing encounters.
Galaxy's query preview and AI optimizer encourage smaller, efficient result sets, and its connection manager surfaces timeout settings so you can adjust them before running heavy jobs.
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