3.3 Redis Slow Queries

1. Redis Command Execution Flow

• The client sends a command to the server.
• The server queues the command.
• The server executes the command.
  • Slow-query statistics measure this time.
• The server returns the result.

2. Usage

2.1. Record Slow Queries

# Slow queries are recorded in an in-memory queue. Generally set to 1000
slowlog-max-len=1000
# Threshold, in microseconds. Generally set to 1 ms
slow-log-slower-than=10000

2.2. Slow-Query Commands

slowlog get [n]
slowlog len
slowlog reset

2.3. Analyze the Cause of Slow Queries

• Redis bigkey

3. Implementation

A first-in-first-out queue stored in memory.