postgresql - PostgreSQL 和 GlusterFS 性能测试报错

Question

我正在使用 pgbench 进行性能测试，以评估将 Glusterfs 与 Postgresql 结合使用的影响。我用 3 个砖 block /服务器创建了一个 gluster 复制卷:

Volume Name: gv0
Type: Replicate
Volume ID: a7e617ec-c564-4a01-aec9-807e87fcccb3
Status: Started
Snapshot Count: 0
Number of Bricks: 1 x 3 = 3
Transport-type: tcp
Bricks:
Brick1: 10.112.76.37:/export/sdb1/brick
Brick2: 10.112.76.38:/export/sdb1/brick
Brick3: 10.112.76.39:/export/sdb1/brick
Options Reconfigured:
transport.address-family: inet
nfs.disable: on
performance.client-io-threads: off

之后，我将 postgres 配置为使用卷 gv0。在低压力下一切正常。但是，当负载增加时，会出现以下错误:

client 14 aborted in state 9: ERROR:  unexpected data beyond EOF in block 0 of relation base/16384/16503
HINT:  This has been seen to occur with buggy kernels; consider updating your system.
client 7 aborted in state 9: ERROR:  unexpected data beyond EOF in block 0 of relation base/16384/16503
HINT:  This has been seen to occur with buggy kernels; consider updating your system.
client 5 aborted in state 9: ERROR:  unexpected data beyond EOF in block 0 of relation base/16384/16503
HINT:  This has been seen to occur with buggy kernels; consider updating your system.
client 6 aborted in state 9: ERROR:  unexpected data beyond EOF in block 0 of relation base/16384/16503
HINT:  This has been seen to occur with buggy kernels; consider updating your system.
client 8 aborted in state 9: ERROR:  unexpected data beyond EOF in block 0 of relation base/16384/16503
HINT:  This has been seen to occur with buggy kernels; consider updating your system.
client 0 aborted in state 9: ERROR:  unexpected data beyond EOF in block 0 of relation base/16384/16503
HINT:  This has been seen to occur with buggy kernels; consider updating your system.
client 11 aborted in state 9: ERROR:  unexpected data beyond EOF in block 0 of relation base/16384/16503
HINT:  This has been seen to occur with buggy kernels; consider updating your system.

知道是什么原因造成的吗？

Answer 1

Gluster 不支持“结构化数据”，如 GlusterFS Install Guide 中所述:

Gluster does not support so called “structured data”, meaning live, SQL databases. Of course, using Gluster to backup and restore the database would be fine - Gluster is traditionally better when using file sizes at of least 16KB (with a sweet spot around 128KB or so).

我的猜测是，当负载较小时，Gluster 可以跟上复制的速度，但当负载增加到超过某个点时，就会出现问题，可能会导致裂脑错误。

您可以使用命令 gluster volume heal <volume_name> info split-brain 查看裂脑中的文件, 或 gluster volume heal <volume_name> info对于所有需要修复的文件。