MySQL cannot allocate enough memory or swap and stops new connections or operations, raising ER_OUT_OF_RESOURCES (error 1041).
MySQL Error 1041: ER_OUT_OF_RESOURCES means the server ran out of RAM or swap to satisfy a request. Free memory, raise OS limits, increase swap, or tune buffers to resolve the issue.
Out of memory; check if mysqld or some other process uses
MySQL throws “Out of memory; check if mysqld or some other process uses all available memory” when it cannot allocate the memory requested for a client connection, sort, join, or cache operation. The internal identifier is error 1041 with condition name ER_OUT_OF_RESOURCES.
The server aborts the current statement and may refuse new connections. Production workloads stall, so diagnosing and freeing resources quickly is critical.
Insufficient physical RAM is the primary trigger.
High‐traffic workloads, huge buffer sizes, and large temporary tables rapidly consume memory.
Operating-system limits such as ulimit -v or cgroup quotas can cap mysqld memory even when free RAM exists.
Memory leaks in stored routines or plugins occasionally exhaust resources over time.
First, confirm memory pressure with SHOW STATUS LIKE 'Threads_%';, SHOW GLOBAL STATUS LIKE 'Created_tmp%';, and OS tools such as top or free -m.
Free memory by restarting heavy applications, or stop and restart mysqld during a maintenance window if necessary.
Lower MySQL memory usage by shrinking innodb_buffer_pool_size, key_buffer_size, sort_buffer_size, and join_buffer_size.
Raise OS limits with ulimit -v unlimited, enlarge swap space, or move to a machine with more RAM.
Bulk imports that build giant indexes often fail.
Use ALTER TABLE ... DISABLE KEYS, import, then enable keys to reduce memory spikes.
Complex reporting queries may create huge implicit temporary tables. Rewrite queries to use explicit smaller temp tables or add indexes.
Many idle connections still consume thread buffers.
Enable connection pooling in Galaxy or set wait_timeout lower.
Size InnoDB buffer pool to 60-70 percent of RAM, leaving headroom for OS and other buffers.
Monitor memory with performance_schema and set alerts when free RAM drops below 15 percent.
Use Galaxy’s AI copilot to detect missing indexes and rewrite memory-hungry queries before deployment.
Error 1135 (HY000): Host is blocked often appears alongside 1041 when the server refuses new clients.
Error 1040 (ER_TOO_MANY_CONNECTIONS) differs because it signals connection count exhaustion, not memory.
Error 1203 (ER_TOO_MANY_USER_CONNECTIONS) is user-specific but can compound memory pressure.
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Check performance_schema.memory_summary_by_account_by_event_name to see largest consumers. Reduce dynamic per-thread buffers like sort_buffer_size before global buffers.
Yes, disk swap is slower than RAM, but it prevents crashes. Use it as a safety net while planning a proper memory upgrade.
Galaxy can run scheduled queries against performance_schema and send Slack alerts when memory usage crosses thresholds.
No. Lowering global variables with SET GLOBAL and killing idle threads can free memory without downtime if pressure is moderate.
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