CloudSQL PostgreSQL（11/14）高配置下性能及TPS异常低下求助

问题描述 #

我们的CloudSQL PostgreSQL实例（版本11或14）存在性能异常：测试过1vCPU到4vCPU、最高24GB内存、100GB SSD的多种配置，单连接pgbench测试时单请求响应耗时300-500ms，TPS仅2-3。

单连接测试结果 #

transaction type: <builtin: TPC-B (sort of)>
scaling factor: 50
query mode: simple
number of clients: 1
number of threads: 1
duration: 100 s
number of transactions actually processed: 207
latency average = 483.165 ms
initial connection time = 359.565 ms
tps = 2.069685 (without initial connection time)

多连接测试结果 #

多连接时扩展性尚可，但整体性能仍极差：

transaction type: <builtin: TPC-B (sort of)>
scaling factor: 50
query mode: simple
number of clients: 50
number of threads: 50
duration: 100 s
number of transactions actually processed: 9296
latency average = 538.585 ms
initial connection time = 441.047 ms
tps = 92.835803 (without initial connection time)

版本降级后的表现 #

从PG14降级到PG11后，大型基准测试性能提升约15%，但单连接测试仍缓慢。实例未修改任何高级数据库参数，保持默认配置。

本地测试对比 #

本地Mac M1 Pro上的相同测试性能远超云端，差距过大：

transaction type: <builtin: TPC-B (sort of)>
scaling factor: 1
query mode: simple
number of clients: 1
number of threads: 1
maximum number of tries: 1
duration: 30 s
number of transactions actually processed: 4057
number of failed transactions: 0 (0.000%)
latency average = 7.393 ms
initial connection time = 17.055 ms
tps = 135.263939 (without initial connection time)

连接方式与性能期望 #

我们使用最新稳定版cloudsql auth proxy连接，期望单连接TPS达到线上常见的5-10左右。

近机房测试结果 #

在美中地区靠近服务器的机器上测试结果如下：

transaction type: <builtin: TPC-B (sort of)>
scaling factor: 1
query mode: simple
number of clients: 5
number of threads: 1
duration: 30 s
number of transactions actually processed: 207
latency average = 690.794 ms
initial connection time = 2037.796 ms
tps = 7.238044 (without initial connection time)

内容的提问来源于stack exchange，提问作者MorenoMdz