# 故障处理的基本步骤
# 1. 故障上报：及时上报故障情况
# 2. 故障诊断：确定故障原因
# 3. 故障解决：采取措施解决故障
# 4. 故障恢复：恢复系统正常运行
# 5. 故障分析：分析故障原因，防止再次发生
# 6. 故障记录：记录故障处理过程和结果

# 案例1：数据库无法启动
# 检查日志
cat /opengauss/logs/postgresql-*.log风哥提示：

# 检查数据目录权限
ls -la /opengauss/fgdata

# 检查内存使用情况
free -h

# 检查磁盘空间
df -h

# 案例2：数据库连接失败
# 检查数据库状态
gs_ctl status -D /opengauss/fgdata

# 检查网络连接
ping 192.168.1.10

# 检查监听状态
netstat -tuln | grep 5432

# 检查防火墙
firewall-cmd –list-ports

# 案例3：SQL执行缓慢
# 查看正在执行的SQL
SELECT pid, usename, query, state FROM pg_stat_activity WHERE state = ‘active’;

# 分析执行计划
EXPLAIN ANALYZE SELECT * FROM fgedu.fgedu_test WHERE name = ‘test’;
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# 检查索引
SELECT * FROM pg_indexes WHERE tablename = ‘fgedu_test’;

# 案例4：死锁
# 查看锁等待情况
SELECT blocked_locks.pid AS blocked_pid,
blocked_activity.usename AS blocked_user,
blocking_locks.pid AS blocking_pid,
blocking_activity.usename AS blocking_user,
blocked_activity.query AS blocked_query,
blocking_activity.query AS blocking_query
FROM pg_catalog.pg_locks blocked_locks
JOIN pg_catalog.pg_stat_activity blocked_activity ON blocked_activity.pid = blocked_locks.pid
JOIN pg_catalog.pg_locks blocking_locks ON blocking_locks.locktype = blocked_locks.locktype
AND blocking_locks.DATABASE IS NOT DISTINCT FROM blocked_locks.DATABASE
AND blocking_locks.relation IS NOT DISTINCT FROM blocked_locks.relation
AND blocking_locks.page IS NOT DISTINCT FROM blocked_locks.page
AND blocking_locks.tuple IS NOT DISTINCT FROM blocked_locks.tuple
AND blocking_locks.virtualxid IS NOT DISTINCT FROM blocked_locks.virtualxid
AND blocking_locks.transactionid IS NOT DISTINCT FROM blocked_locks.transactionid
AND blocking_locks.classid IS NOT DISTINCT FROM blocked_locks.classid
AND blocking_locks.objid IS NOT DISTINCT FROM blocked_locks.objid
AND blocking_locks.objsubid IS NOT DISTINCT FROM blocked_locks.objsubid
AND blocking_locks.pid != blocked_locks.pid
WHERE NOT blocked_locks.GRANTED;

# 终止阻塞进程
SELECT pg_terminate_backend(pid);

# 定期备份：确保数据安全
# 配置监控：及时发现异常
# 优化参数：提高系统稳定性
# 定期维护：清理垃圾数据，重建索引
# 安全加固：防止安全漏洞
# 制定预案：针对常见故障制定应对方案

# 监控脚本示例学习交流加群风哥QQ113257174
#!/bin/bash
# check_db_status.sh
# from:www.itpux.com.qq113257174.wx:itpux-com
# web: `http://www.fgedu.net.cn`

# 检查数据库状态
STATUS=$(gs_ctl status -D /opengauss/fgdata | grep “服务器状态”)

if [[ $STATUS == *”正常运行”* ]]; then
echo “数据库状态正常”
else
echo “数据库状态异常，需要检查”
# 发送告警
# 这里可以添加发送邮件或短信告警的代码
fi

# 检查磁盘空间
DISK_USAGE=$(df -h | grep /opengauss | awk ‘{print $5}’ | sed ‘s/%//’)

if [ $DISK_USAGE -gt 80 ]; then
echo “磁盘空间不足，使用率：${DISK_USAGE}%”
# 发送告警
else
echo “磁盘空间正常，使用率：${DISK_USAGE}%”
fi