mysql - 巨页无法与 mariadb 一起使用

Question

我们尝试为与 galera 集群一起运行的 mariabdb 设置大页面。我们已经分配了足够高的大页来容纳 innodb 缓冲区。

服务器.conf

[mysqld]
large-pages
innodb_buffer_pool_size =4G

/etc/sysctl.conf

# hugepages information
vm.nr_hugepages = 3072

# Controls the maximum shared segment size, in bytes
kernel.shmmax = 68719476736

# Controls the maximum number of shared memory segments, in pages
kernel.shmall = 4294967296

/etc/security/limits.conf

@mysql      soft    memlock     unlimited
@mysql      hard    memlock     unlimited

免费-m

             total       used       free     shared    buffers     cached
Mem:         11908      11635        272          0         68       5502
-/+ buffers/cache:       6064       5843
Swap:         2559          0       2559

mysqld.log 中的错误

150403  4:46:12 [Note] InnoDB: Initializing buffer pool, size = 4.0G
InnoDB: HugeTLB: Warning: Failed to allocate 687865856 bytes. errno 1
InnoDB HugeTLB: Warning: Using conventional memory pool
InnoDB: HugeTLB: Warning: Failed to allocate 687865856 bytes. errno 1
InnoDB HugeTLB: Warning: Using conventional memory pool
InnoDB: HugeTLB: Warning: Failed to allocate 687865856 bytes. errno 1
InnoDB HugeTLB: Warning: Using conventional memory pool
InnoDB: HugeTLB: Warning: Failed to allocate 687865856 bytes. errno 1
InnoDB HugeTLB: Warning: Using conventional memory pool
InnoDB: HugeTLB: Warning: Failed to allocate 687865856 bytes. errno 1
InnoDB HugeTLB: Warning: Using conventional memory pool
InnoDB: HugeTLB: Warning: Failed to allocate 687865856 bytes. errno 1
InnoDB HugeTLB: Warning: Using conventional memory pool
InnoDB: HugeTLB: Warning: Failed to allocate 687865856 bytes. errno 1
InnoDB HugeTLB: Warning: Using conventional memory pool
InnoDB: HugeTLB: Warning: Failed to allocate 687865856 bytes. errno 1
InnoDB HugeTLB: Warning: Using conventional memory pool
150403  4:46:13 [Note] InnoDB: Completed initialization of buffer pool

cat/proc/meminfo |grep -i 巨大

AnonHugePages:         0 kB
HugePages_Total:       3072
HugePages_Free:        3072
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB

Answer 1

我发现您的配置中缺少一个步骤:您需要设置可以访问 HugeTLB 内存的(mysql 的)组号。

检查当前分配的值:

$ sysctl vm.hugetlb_shm_group

这可能只会返回 0，即“root”组。您应该创建一个hugetlb 组并将mysql 添加到该组，或者使用mysql 所属的组之一。无论哪个组，使用其 GID(分别使用 grep '^hugetlb:'/etc/group | cut -d: -f3 或 id -g mysql)并执行:

# sysctl -w vm.hugetlb_shm_group=<gid>

(替换为您所在组的 GID)

测试它是否有效，它确实将以下行添加到/etc/sysctl.conf (或/etc/sysctl.d/下的新文件中):

vm.hugetlb_shm_group = <gid>