Introduction

MySQL InnoDB redo log full when checkpointing lagging behind write rate. This guide provides step-by-step diagnosis and resolution.

Symptoms

Typical error output:

bash
Error: Database operation failed
Check database logs for detailed error message
SELECT * FROM sys.dm_os_wait_stats

Common Causes

  1. 1.Resource configuration insufficient for workload
  2. 2.Locking or blocking preventing operation
  3. 3.Network or disk I/O bottleneck
  4. 4.Index or query optimization needed

Step-by-Step Fix

Step 1: Check Current State

sql
-- Check database status
SHOW STATUS LIKE '%error%';
SELECT * FROM information_schema.processlist WHERE time > 10;
-- Review logs

Step 2: Identify Root Cause

sql
-- Check for blocking processes
SELECT * FROM pg_stat_activity WHERE state != 'idle';
SELECT * FROM information_schema.processlist WHERE time > 30;

Step 3: Apply Primary Fix

```sql -- Primary fix -- Update configuration ALTER SYSTEM SET parameter = value;

-- Verify the change SELECT current_setting('parameter'); ```

Step 4: Apply Alternative Fix

```sql -- Alternative fix: Check configuration SELECT * FROM pg_settings WHERE name LIKE '%vacuum%';

-- Adjust parameters dynamically ALTER SYSTEM SET autovacuum_vacuum_cost_delay = 10; SELECT pg_reload_conf();

-- Verify the fix SELECT * FROM pg_stat_user_tables WHERE relname = 'target_table'; ```

Step 5: Verify the Fix

sql
-- Verify fix
SELECT * FROM pg_stat_user_tables WHERE relname = 'table';
SHOW STATUS LIKE '%parameter%';
-- Check logs for success

Common Pitfalls

  • Running vacuum during peak hours without resource management
  • Forgetting to analyze after vacuum for statistics update
  • Not monitoring autovacuum progress on large tables
  • Setting cost delay too high for high-churn tables

Best Practices

  • Schedule maintenance windows for vacuum full operations
  • Monitor bloat ratio and autovacuum frequency
  • Tune autovacuum parameters per table based on churn rate
  • Use pg_stat_progress_vacuum to monitor vacuum progress
  • PostgreSQL Autovacuum Not Running
  • PostgreSQL Dead Tuple Accumulation
  • PostgreSQL Transaction ID Wraparound
  • PostgreSQL Table Size Excessive