MySQL blocks the client host after too many failed or interrupted connections, raising error 1129 until the administrator executes FLUSH HOSTS or increases the max_connect_errors limit.
MySQL Error 1129: ER_HOST_IS_BLOCKED means the server stopped accepting connections from your IP because it exceeded max_connect_errors. Run FLUSH HOSTS or mysqladmin flush-hosts, lower connection errors, and tune max_connect_errors to restore access.
Host '%s' is blocked because of many connection errors;
Error 1129 appears when MySQL refuses new connections from a specific client host after it exceeds the max_connect_errors threshold. The server returns the message: “Host 'your_ip' is blocked because of many connection errors; unblock with 'mysqladmin flush-hosts'”.
The block protects MySQL against brute-force logins, network flapping, or faulty applications that open and drop connections rapidly.
Until the administrator clears the block, every connection attempt from that IP fails immediately.
Frequent authentication failures, dropped TCP handshakes, or abrupt client disconnects increment the Host_cache error counter. When the counter passes max_connect_errors (default 100), MySQL inserts the host into the Host_cache with a Blocked status and raises error 1129.
Poor network quality, misconfigured connection pools, or scripts that open many short-lived sessions often trigger the limit.
MySQL versions 5.7+ also count SSL negotiation errors, making secure connections vulnerable to the block if certificates mismatch.
First, confirm that your IP is blocked by querying performance_schema.host_cache or SHOW STATUS LIKE 'Host_cache_miss_rate'. Next, run FLUSH HOSTS or mysqladmin flush-hosts as a privileged user. This clears the Host_cache and removes the block immediately.
After unblocking, investigate aborted connections via SHOW STATUS LIKE 'Aborted_connects' and the MySQL error log.
Adjust the client code, network settings, or authentication credentials to stop the error counter from rising again.
High-traffic web servers with a misconfigured connection pool often recycle thousands of connections. Lower the pool size, enable keep-alive, or switch to persistent connections to prevent rapid churn.
Containers that restart frequently can hit the limit during health checks.
Add the --max_connect_errors 10000 flag to mysqld or set the variable in my.cnf to allow more retries.
Monitor Aborted_connects and Host_cache statistics with PROMETHEUS or MySQL Enterprise Monitor. Alert when the counter approaches the threshold. In Galaxy’s SQL editor, you can schedule a health-check query to track these metrics and share it with your team.
Raise max_connect_errors only after fixing root-cause.
Keep firewalls stable, reuse connections, and handle authentication errors gracefully in application code.
Error 1040 “Too many connections” occurs when the global connection limit is reached. Increase max_connections or tune connection pooling.
Error 1130 “Host is not allowed to connect” signals a privileges issue. Grant the proper HOST or use '%' wildcard in the mysql.user table.
.
Query performance_schema.host_cache filtering on host_block_reason = 'blocked' or check the MySQL error log for the exact IP.
No. FLUSH HOSTS only clears the internal Host_cache. Existing sessions remain unaffected.
Yes, but consider it a temporary workaround. Always investigate why errors accumulate before raising the limit permanently.
Galaxy allows you to run recurring monitoring queries and share alerts, ensuring teams act before the host gets blocked.
.avif)
.avif){kind=logo}
