PostgreSQL DBA(96) - System Conf(client_min_messages)

2025-04-10 技术教程

PostgreSQL提供了参数client_min_messages用以控制返回给客户的消息级别，不同的级别返回的消息大小不同，默认为NOTICE。在通常情况下，如果客户端执行的SQL语句不频繁的话，使用默认参数即可，但如果客户端执行大量的SQL，设置该参数为较高级别就显得有意义了：可以减少消息的大小从而降低网络负载，提升吞吐。

参数简介
下面创建一个存储过程，raise notice显示通知信息

[local]:5432 pg12@testdb=# CREATE OR REPLACE FUNCTION foo() RETURNS void ASpg12@testdb-# $$pg12@testdb$# BEGINpg12@testdb$# RAISE NOTICE 'some message';pg12@testdb$# RETURN;pg12@testdb$# END;pg12@testdb$# $$ LANGUAGE 'plpgsql';CREATE FUNCTIONTime: 389.227 ms[local]:5432 pg12@testdb=#

执行存储过程

[local]:5432 pg12@testdb=# show client_min_messages; client_min_messages --------------------- notice(1 row)Time: 0.589 ms[local]:5432 pg12@testdb=# select foo();NOTICE: some message foo -----(1 row)Time: 26.838 ms[local]:5432 pg12@testdb=# set client_min_messages='ERROR';SETTime: 0.361 ms[local]:5432 pg12@testdb=# select foo(); foo -----(1 row)Time: 1.638 ms[local]:5432 pg12@testdb=#

在client_min_messages设置为ERROR后，不再显示NOTICE通知信息。
下面使用benchmarksql压测工具测试该参数从NOTICE修改为ERROR后的性能变化。
1.NOTICE

[xdb@localhost run]$ ./runBenchmark.sh props.pg2019-09-25 12:15:25,434 INFO - Term-00, 2019-09-25 12:15:25,435 INFO - Term-00, +-------------------------------------------------------------+2019-09-25 12:15:25,435 INFO - Term-00, BenchmarkSQL v4.1.12019-09-25 12:15:25,435 INFO - Term-00, +-------------------------------------------------------------+2019-09-25 12:15:25,435 INFO - Term-00, (c) 2003, Raul Barbosa2019-09-25 12:15:25,435 INFO - Term-00, (c) 2004-2016, Denis Lussier2019-09-25 12:15:25,435 INFO - Term-00, (c) 2016, Jan Wieck2019-09-25 12:15:25,435 INFO - Term-00, +-------------------------------------------------------------+2019-09-25 12:15:25,435 INFO - Term-00, 2019-09-25 12:15:25,435 INFO - Term-00, driver=org.postgresql.Driver2019-09-25 12:15:25,435 INFO - Term-00, conn=jdbc:postgresql://192.168.26.28:5432/benchmarkdb2019-09-25 12:15:25,435 INFO - Term-00, user=pg122019-09-25 12:15:25,435 INFO - Term-00, 2019-09-25 12:15:25,435 INFO - Term-00, warehouses=322019-09-25 12:15:25,435 INFO - Term-00, terminals=202019-09-25 12:15:25,435 INFO - Term-00, runMins=52019-09-25 12:15:25,435 INFO - Term-00, limitTxnsPerMin=02019-09-25 12:15:25,435 INFO - Term-00, 2019-09-25 12:15:25,435 INFO - Term-00, newOrderWeight=452019-09-25 12:15:25,435 INFO - Term-00, paymentWeight=432019-09-25 12:15:25,435 INFO - Term-00, orderStatusWeight=4 Term-00, Running Average 2019-09-25 12:20:25,706 INFO - Term-00, 52216 Memory Usage: 26MB / 37MB 2019-09-25 12:20:25,706 INFO - Term-00, 2019-09-25 12:20:25,707 INFO - Term-00, Measured tpmC (NewOrders) = 7448.89 2019-09-25 12:20:25,707 INFO - Term-00, Measured tpmTOTAL = 16626.58 2019-09-25 12:20:25,707 INFO - Term-00, Session Start = 2019-09-25 12:15:252019-09-25 12:20:25,707 INFO - Term-00, Session End = 2019-09-25 12:20:252019-09-25 12:20:25,707 INFO - Term-00, Transaction Count = 83171[xdb@localhost run]$ [xdb@localhost run]$

2.ERROR

[xdb@localhost run]$ ./runBenchmark.sh props.pg2019-09-25 12:22:57,954 INFO - Term-00, 2019-09-25 12:22:57,954 INFO - Term-00, +-------------------------------------------------------------+2019-09-25 12:22:57,954 INFO - Term-00, BenchmarkSQL v4.1.12019-09-25 12:22:57,954 INFO - Term-00, +-------------------------------------------------------------+2019-09-25 12:22:57,954 INFO - Term-00, (c) 2003, Raul Barbosa2019-09-25 12:22:57,955 INFO - Term-00, (c) 2004-2016, Denis Lussier2019-09-25 12:22:57,955 INFO - Term-00, (c) 2016, Jan Wieck2019-09-25 12:22:57,955 INFO - Term-00, +-------------------------------------------------------------+2019-09-25 12:22:57,955 INFO - Term-00, 2019-09-25 12:22:57,955 INFO - Term-00, driver=org.postgresql.Driver2019-09-25 12:22:57,955 INFO - Term-00, conn=jdbc:postgresql://192.168.26.28:5432/benchmarkdb2019-09-25 12:22:57,955 INFO - Term-00, user=pg122019-09-25 12:22:57,955 INFO - Term-00, 2019-09-25 12:22:57,955 INFO - Term-00, warehouses=322019-09-25 12:22:57,955 INFO - Term-00, terminals=202019-09-25 12:22:57,955 INFO - Term-00, runMins=52019-09-25 12:22:57,955 INFO - Term-00, limitTxnsPerMin=02019-09-25 12:22:57,955 INFO - Term-00, 2019-09-25 12:22:57,955 INFO - Term-00, newOrderWeight=452019-09-25 12:22:57,955 INFO - Term-00, paymentWeight=432019-09-25 12:22:57,955 INFO - Term-00, orderStatusWeight=4 Term-00, Running Average 2019-09-25 12:27:58,267 INFO - Term-00, 79156 Memory Usage: 18MB / 37MB 2019-09-25 12:27:58,267 INFO - Term-00, 2019-09-25 12:27:58,267 INFO - Term-00, Measured tpmC (NewOrders) = 7815.72 2019-09-25 12:27:58,267 INFO - Term-00, Measured tpmTOTAL = 17440.12 2019-09-25 12:27:58,267 INFO - Term-00, Session Start = 2019-09-25 12:22:582019-09-25 12:27:58,267 INFO - Term-00, Session End = 2019-09-25 12:27:582019-09-25 12:27:58,268 INFO - Term-00, Transaction Count = 87254[xdb@localhost run]$

TPMC 7815 vs 7448，提升比例为4.9%

为免系统随机扰动导致的误差，重新测试了一遍

-- NONE2019-09-25 14:53:05,384 INFO - Term-00, Measured tpmC (NewOrders) = 7168.43 2019-09-25 14:53:05,384 INFO - Term-00, Measured tpmTOTAL = 15890.5 2019-09-25 14:53:05,384 INFO - Term-00, Session Start = 2019-09-25 14:48:052019-09-25 14:53:05,385 INFO - Term-00, Session End = 2019-09-25 14:53:052019-09-25 14:53:05,385 INFO - Term-00, Transaction Count = 79491[xdb@localhost run]$ -- vacuum full;-- client_min_messages=error2019-09-25 14:44:29,101 INFO - Term-00, Measured tpmC (NewOrders) = 7239.02 2019-09-25 14:44:29,101 INFO - Term-00, Measured tpmTOTAL = 16079.06 2019-09-25 14:44:29,101 INFO - Term-00, Session Start = 2019-09-25 14:39:282019-09-25 14:44:29,102 INFO - Term-00, Session End = 2019-09-25 14:44:292019-09-25 14:44:29,102 INFO - Term-00, Transaction Count = 80434-- vacuum full;-- update_process_title=off-- track_activities=off2019-09-25 15:01:11,861 INFO - Term-00, Measured tpmC (NewOrders) = 7253.43 2019-09-25 15:01:11,861 INFO - Term-00, Measured tpmTOTAL = 16111.73 2019-09-25 15:01:11,862 INFO - Term-00, Session Start = 2019-09-25 14:56:112019-09-25 15:01:11,862 INFO - Term-00, Session End = 2019-09-25 15:01:112019-09-25 15:01:11,862 INFO - Term-00, Transaction Count = 80584-- vacuum full;-- client_min_messages=error-- update_process_title=off-- track_activities=off2019-09-25 15:08:46,923 INFO - Term-00, Measured tpmC (NewOrders) = 7194.55 2019-09-25 15:08:46,923 INFO - Term-00, Measured tpmTOTAL = 16059.38 2019-09-25 15:08:46,923 INFO - Term-00, Session Start = 2019-09-25 15:03:462019-09-25 15:08:46,923 INFO - Term-00, Session End = 2019-09-25 15:08:462019-09-25 15:08:46,923 INFO - Term-00, Transaction Count = 80350

似乎没有什么效果。

参考资料
Reducing log messages on the client