无法在 CentOS 7 上启动 MongoDB 3.0.2 服务

Unable to start MongoDB 3.0.2 service on CentOS 7

我们正在为 Amazon EC2 实例上的生产环境设置 MongoDB 服务器,但无法启动该服务。我已按照 this 文档进行设置。以下是我设置服务器的步骤:

/etc/yum.repos.d/mongodb-org-3.0.repo

中添加了以下内容
[mongodb-org-3.0]
name=MongoDB Repository
baseurl=http://repo.mongodb.org/yum/redhat/$releasever/mongodb-org/3.0/x86_64/
gpgcheck=0
enabled=1

并使用 sudo yum install -y mongodb-org-3.0.2

安装了 MongoDB 3.0.2

为数据、日志和日志创建了三个分区:

sudo mkdir /mongo
sudo mkdir /mongo/data
sudo mkdir /mongo/log
sudo mkdir /mongo/journal

为三个单独的分区创建了文件系统:

sudo mkfs.ext4 /dev/xvdb
sudo mkfs.ext4 /dev/xvdc
sudo mkfs.ext4 /dev/xvdd

fstab 中为重新启动创建了条目:

echo '/dev/xvdb /mongo/data ext4 defaults,auto,noatime,noexec 0 0
/dev/xvdc /mongo/journal ext4 defaults,auto,noatime,noexec 0 0
/dev/xvdd /mongo/log ext4 defaults,auto,noatime,noexec 0 0' | sudo tee -a /etc/fstab

并挂载分区:

sudo mount /mongo/data
sudo mount /mongo/journal
sudo mount /mongo/log

授予权限并创建 link

sudo chown mongod:mongod /mongo/data /mongo/journal /mongo/log
sudo ln -s /mongo/journal /mongo/data/journal

已配置 ulimit 并预读上述文档 link 中给出的设置。已验证的权限和分区:

[deployer@prod-mongo ~]$ df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/xvda1      8.0G  1.3G  6.8G  16% /
devtmpfs        3.6G     0  3.6G   0% /dev
tmpfs           3.5G     0  3.5G   0% /dev/shm
tmpfs           3.5G   57M  3.4G   2% /run
tmpfs           3.5G     0  3.5G   0% /sys/fs/cgroup
/dev/xvdc       7.8G   36M  7.3G   1% /mongo/journal
/dev/xvdb       150G   51M  149G   1% /mongo/data
/dev/xvdd       3.9G   16M  3.6G   1% /mongo/log

权限:

[deployer@prod-mongo ~]$ ll /
total 32
lrwxrwxrwx.   1 root   root      7 Sep 29  2014 bin -> usr/bin
dr-xr-xr-x.   4 root   root   4096 Sep 29  2014 boot
drwxr-xr-x.  17 root   root   2860 May 11 12:11 dev
lrwxrwxrwx.   1 root   root      7 Sep 29  2014 lib -> usr/lib
lrwxrwxrwx.   1 root   root      9 Sep 29  2014 lib64 -> usr/lib64
drwxr-xr-x.   2 root   root      6 Jun 10  2014 mnt
drwxr-xr-x.   5 mongod mongod   41 May 11 05:06 mongo
drwxr-xr-x.  21 root   root    660 May 11 12:47 run
lrwxrwxrwx.   1 root   root      8 Sep 29  2014 sbin -> usr/sbin

里面/mongo

[deployer@prod-mongo ~]$ ll /mongo/
total 12
drwxr-xr-x. 3 mongod mongod 4096 May 11 07:33 data
drwxr-xr-x. 3 mongod mongod 4096 May 11 07:31 journal
drwxr-xr-x. 3 mongod mongod 4096 May 11 08:58 log

更改内部配置后/etc/mongodb.conf

logpath=/mongo/log/mongod.log
dbpath=/mongo/data

当我这样做时:sudo service mongod start,我收到了这个错误:

Starting mongod (via systemctl):  Job for mongod.service failed. See 'systemctl status mongod.service' and 'journalctl -xn' for details.
                                                           [FAILED]

进一步记录:

[deployer@prod-mongo ~]$ sudo systemctl status mongod.service

mongod.service - SYSV: Mongo is a scalable, document-oriented database.
   Loaded: loaded (/etc/rc.d/init.d/mongod)
   Active: failed (Result: exit-code) since Tue 2015-05-12 04:42:10 UTC; 42s ago
  Process: 22881 ExecStart=/etc/rc.d/init.d/mongod start (code=exited, status=1/FAILURE)

May 11 04:42:10 ip-xx-xx-xx-xx.local runuser[22887]: pam_unix(runuser:session): session opened for user mongod by (uid=0)
May 11 04:42:10 ip-xx-xx-xx-xx.localdomain runuser[22887]: pam_unix(runuser:session): session closed for user mongod
May 11 04:42:10 ip-xx-xx-xx-xx.local mongod[22881]: Starting mongod: [FAILED]
May 11 04:42:10 ip-xx-xx-xx-xx.local systemd[1]: mongod.service: control process exited, code=exited status=1
May 11 04:42:10 ip-xx-xx-xx-xx.local systemd[1]: Failed to start SYSV: Mongo is a scalable, document-oriented database..
May 11 04:42:10 ip-xx-xx-xx-xx.local systemd[1]: Unit mongod.service entered failed state.

我关注了各种文章和博客文章以及 StackExchange 的答案,但没有找到任何解决方案。我错过了什么吗?

更新:如果我直接运行来自普通用户的mongodb服务是这样的:sudo mongod --logpath ~/mongod.log --dbpath ~/mongodata,那么这个服务正常启动。

我们尝试将 pid 文件的路径更改为另一个目录,这也没有帮助。

我猜你运行正在使用 SELinux(也许是 RHEL 或 CentOS 7?)LinuxLinux

如果是这样,问题是您的 /mongo/ 目录没有允许访问守护进程(如 mongod 服务)的许可策略。

来自维基百科:

SELinux can potentially control which activities a system allows each user, process and daemon, with very precise specifications. However, it is mostly used to confine daemons[citation needed] like database engines or web servers that have more clearly defined data access and activity rights. This limits potential harm from a confined daemon that becomes compromised. Ordinary user-processes often run in the unconfined domain, not restricted by SELinux but still restricted by the classic Linux access rights

要检查这是否是问题所在,请在 shell:

试试这个

sudo setenforce 0

这应该禁用 SELinux 策略并允许服务 运行。

有关更永久的解决方案,请参阅 https://wiki.centos.org/HowTos/SELinux

万一有人在 MongoDB 启动时遇到同样的问题,这里是评论线程 https://jira.mongodb.org/browse/SERVER-18439。此问题计划在 3.1.

中修复

我 运行 解决了这个问题,实际上找到了适合我的解决方案。

简而言之,mongodb 3.2 使用用户 'mongod',而旧版本使用 'mongodb'。一些文件和目录归 'mongodb'(旧用户)所有。一旦我将它们更改为 'mongod' 用户,我就能够使用 systemctl 来控制 mongod 进程。

更具体地说,是“/var/log/mongodb/*”文件的用户所有权错误。

root@<HOST>:# ls -alh /var/log/mongodb
total 664K
drwxr-xr-x   2 mongod  mongod  4.0K Oct 27 12:08 .
drwxr-xr-x. 22 root    root    4.0K Oct 27 11:51 ..
-rw-r--r--   1 mongodb mongodb 3.8K Oct 27 11:48 mongod.log
-rw-r--r--   1 mongodb mongodb  19K Apr 14  2016 mongod.log.2016-04-14T18-29-34
-rw-r--r--   1 mongodb mongodb 2.8K Apr 14  2016 mongod.log.2016-04-14T18-30-13
-rw-r--r--   1 mongodb mongodb  12K Apr 14  2016 mongod.log.2016-04-14T22-27-27
-rw-r--r--   1 mongodb mongodb  11K Apr 14  2016 mongod.log.2016-04-14T22-29-12
-rw-r--r--   1 mongodb mongodb 5.6K Apr 18  2016 mongod.log-20160418.gz
-rw-r--r--   1 mongodb mongodb    0 Apr 18  2016 mongod.log.2016-09-09T17-33-48
-rw-r--r--   1 mongodb mongodb 3.6K Sep  9 11:34 mongod.log.2016-09-09T17-34-52
-rw-r--r--   1 mongodb mongodb  23K Sep  9 11:49 mongod.log.2016-09-09T17-49-49
-rw-r--r--   1 mongodb mongodb 5.0K Sep  9 11:55 mongod.log.2016-09-09T17-55-15
-rw-r--r--   1 mongodb mongodb 5.0K Sep  9 12:02 mongod.log.2016-09-09T18-02-26
-rw-r--r--   1 mongodb mongodb 5.0K Sep  9 12:13 mongod.log.2016-09-09T18-13-17
-rw-r--r--   1 mongodb mongodb 5.0K Sep  9 12:25 mongod.log.2016-09-09T18-25-01
-rw-r--r--   1 mongodb mongodb 5.2K Sep  9 12:47 mongod.log.2016-09-09T18-47-54
-rw-r--r--   1 mongodb mongodb 5.0K Sep  9 12:52 mongod.log.2016-09-09T18-52-16
-rw-r--r--   1 mongodb mongodb 5.0K Sep  9 12:54 mongod.log.2016-09-09T18-54-49
-rw-r--r--   1 mongodb mongodb 5.0K Sep  9 13:01 mongod.log.2016-09-09T19-01-22
-rw-r--r--   1 mongodb mongodb 3.0K Sep  9 13:03 mongod.log.2016-09-09T19-03-21
-rw-r--r--   1 mongodb mongodb 215K Sep  9 14:25 mongod.log.2016-09-09T20-25-59
-rw-r--r--   1 mongodb mongodb 281K Sep 10 03:42 mongod.log-20160910
-rw-r--r--   1 mongodb mongodb    0 Sep 10 03:42 mongod.log.2016-10-27T17-42-42
-rw-r-----   1 mongod  mongod     0 Sep 29 22:03 mongod.log.rpmnew

注意目录的所有者是 'mongod'(新用户),而日志文件全部归 'mongodb'(旧用户)所有。