How to fix ERROR 1317: Query execution was interrupted in MySQL

-- Show all current connections
SHOW PROCESSLIST;

-- Look for your query (or similar queries) and note the ID column
-- To see more details:
SHOW FULL PROCESSLIST;

-- To prevent future kills, note who has PROCESS privilege:
SELECT user, host FROM mysql.user WHERE Process_priv='Y';

-- Check max_execution_time (MySQL 5.7.7+)
SHOW VARIABLES LIKE 'max_execution_time';

-- Check connect_timeout and read_timeout
SHOW VARIABLES LIKE '%timeout%';

-- If max_execution_time is very small, increase it:
SET SESSION max_execution_time=300000;  -- 300 seconds

-- For persistent change, add to my.cnf:
-- max_execution_time=300000

-- Enable slow query log if not already enabled
SET GLOBAL slow_query_log='ON';
SET GLOBAL long_query_time=5;  -- Log queries taking > 5 seconds

-- Run your problematic query and check the slow query log
-- On Linux:
-- tail -50 /var/log/mysql/slow.log

-- Analyze the slow query
EXPLAIN SELECT ...;

-- Check for missing indexes
EXPLAIN FORMAT=JSON SELECT ...;

# If using MySQL CLI, avoid interrupts:
# - Do not close the terminal window
# - Do not press Ctrl+C
# - Disable SSH timeout by adjusting ServerAliveInterval

# For SSH connections:
ssh -o ServerAliveInterval=60 user@host

# For application code (example in Python):
# Increase connection timeout
connection = mysql.connector.connect(
    host="localhost",
    user="user",
    password="password",
    database="db",
    connection_timeout=300,
    autocommit=False
)

# Python example using mysql-connector-python
import mysql.connector
import time

def execute_with_retry(query, max_retries=3):
    for attempt in range(max_retries):
        try:
            cursor = connection.cursor()
            cursor.execute(query)
            return cursor.fetchall()
        except mysql.connector.Error as err:
            if err.errno == 1317:  # Query execution was interrupted
                print(f"Query interrupted (attempt {attempt + 1}), retrying...")
                time.sleep(2 ** attempt)  # Exponential backoff
            else:
                raise
    raise Exception("Query failed after max retries")

// Using mysql2
async function executeWithRetry(query, maxRetries = 3) {
  for (let attempt = 0; attempt < maxRetries; attempt++) {
    try {
      return await connection.promise().query(query);
    } catch (error) {
      if (error.errno === 1317) {
        console.log(`Query interrupted (attempt ${attempt + 1}), retrying...`);
        await new Promise(resolve => setTimeout(resolve, 1000 * Math.pow(2, attempt)));
      } else {
        throw error;
      }
    }
  }
  throw new Error('Query failed after max retries');
}

-- Show replica status
SHOW SLAVE STATUS\G

-- Look for:
-- - Seconds_Behind_Master: High values indicate lag
-- - Slave_SQL_Running: Should be YES
-- - Last_Error: May show Error 1317

-- Check replication filters that might be killing queries
SHOW VARIABLES LIKE 'slave_kill_allow_all';

-- View recent replication errors
SHOW ENGINE INNODB STATUS;

-- If replica is far behind, consider:
-- 1. Increasing slave_parallel_workers (MySQL 5.7+)
-- 2. Skipping problematic queries if safe
-- 3. Rebuilding the replica from a fresh backup