I have a sharded MongoDB cluster setup running under a single mongos instance. I have added another mongos instance which runs fine with existing configuration.
Problem: I want the two mongos instances to be automatically started when the system reboots.
So far I have created a bash script to start the server and added a crontab entry which supposed to run this bash script at the system startup. But the script is no longer executed by crontab. No log entries or no any errors.
Why is the script not running by CRON? When I manually run the script using bashcommand, it runs fine and starts the server without any problem.
The script looks like below:
#!/bin/bash
mongos --configdb "config0:27020,config1:27020,config2:27020" --port "27017" --logpath "/data/mongodb.log" &
And the crontab entry is:
#reboot /startMongos.sh
Related
I am trying to configure a replica set on windows as a service, means that even the PC will restart the mongod will run again automatically.
problem is that I run the mongod like this:
mongod --dbpath "C:\Program Files\MongoDB\Server\4.2\data" --logpath "C:\Program Files\MongoDB\Server\4.2\log\mongod.log" --port 27017 --storageEngine=wiredTiger --journal --replSet test_replica
And once I close the CMD running this command the service is killed. How do I run it correctly then?
Also, currenctly the service is navigating to the default cfg file but I see the replication there is marked with # (so the service is running as standalone). and when I try to add to replication the replSet: test_replica it won't start anymore.
You should put all your parameters into a configuration file. Then you can create the service like this:
mongod.exe --config c:\MongoDB\config\mongod.cfg --install
For a replica set you typically create several services, not just one. It is possible to run a replica set with just one member, however this is quite useless. Of course, when you create several services then each one needs his own config file (and also his own dbPath, port, etc.)
The next time your PC will boot, the mongo service should also start. Or start it manually with command net start <mongo service name>
You should install mongodb as windows service. Read the guide from the official documentation
Setting --replSet from command line or replication:replSetName in configuration file is not enough. Read this guide, in short: after mongodb process is started in replica set mode, you should run rs.initiate() in mongo shell.
I'm using Ubuntu 16.04, and I can't understand what's difference between using
sudo service mongod start
and
mongod
In mongodb official documentation here
said that to start mongodb just use sudo service mongod start, and its log stores in /var/log/mongodb. However, I try to run mongodb using mongod this way, log shows on terminal, and after I turn off the terminal, I can not find the log file.
It is confused.
sudo - Runs the command as root.
service - Manages the following program as a daemon (background process).
mongod - Obviously the MongoDB program in question.
start - A command that tells service what to do with the program in question.
Together, we get "I want to start mongod as a background process, and I want to run it as root so it has permission to do the things it needs to do". Running mongod by itself, however, runs the program in an ordinary fashion, i.e. as a foreground process. Typically you want to run it as a background process so that you're free to do other things, e.g. connecting to the database via shell access.
This is pretty simplified, but it should explain what you actually need to know at this point in time.
I unable to start MonogoDB service after adding users into admin db as well as my db.
I setup MonogoDB and started service using following command i.e.
service mongod start
Using command prompt, I added few users like dbOwner, clusterAdmin, readWrite, read roles base users. Along with that I also changed configuration from /etc/mongod.conf. in that file, I changed port number, IP addresses, dbPath, and security.authorization: enabled.
Then I restarted mongod service using following command.
service mongod restart
After ran this command, mongod service stopped successfully, but failed to start with only 'FAILED' message.
I tried execute following command i.e.
mongod --port 27123 --dbpath /path/to/db --auth
It is working.
Question: How to execute 'service mongod start' using additional parameters in CentOS?
MonogoDB: 3.4
OS: CentOS 7
I got solution i.e.
mongod --config /etc/mongod.conf
Referred: https://docs.mongodb.com/manual/reference/configuration-options/#use-the-configuration-file
It starts child process and also I can stop mongod service using service mongod stop command.
But I don't know whether it is correct or not.
I can't certify exactly where the script that "service" command uses on CentOS 7, but in Ubuntu 18.04 mongod service script file is in
/lib/systemd/system/mongod.service
There you can change the user who executes the process and add any parameters you want, like --auth.
Said that, if you ever executed mongod as root, some files on where you store the db data will have the owner as root, making the database fail to start as another user. The fix I found for that is to manually chown to mongodb:mongodb (or the user you want to use) all the files that are owned by root inside the database.
Hope this helps.
mongod.service file from mongodb github
I use to run the mongodb service with the command ( in CentOS)
sudo mongod --config /etc/mongod.conf
in mongod.conf file replica set information are there.
Now when my system is rebooted, I want automatically this service to run.
How can I do this ?
The /etc/rc.d/rc.local script is executed by the init command at boot time or when changing runlevels. Any command that you want to run after reboot can be added in this file. Just add the command at the end of the file /etc/rc.d/rc.local
You should also check the section Using a Basic Init Script in the following link: https://www.linode.com/docs/databases/mongodb/use-mongodb-to-store-application-data-on-centos-5/
I've completed this tutorial and successfully deployed a 3 node replica set. I can connect to it from other hosts and all is good. The question I have is that in the tutorial it states
Start MongoDB
Once the configuration files have been edited, start the database process manual:mongod on each instance by:
Log on onto the instance
Run the following command to start the process:
mongod --config /etc/mongod.conf
This should start the manual:mongod process
To me this seems as though the replica set is running as a user process and not as a system service as in the command
sudo service mongodb start
So what happens if one of the machines reboots? Is that process dead? How can I configure the whole replica set to run as a service?
On machine reboots, the mongod process will stop and you have to restart it.
In system scripts, I am not sure if on box restarts, mongod restart is automatically taken care of or not. But you can have service scripts for mongod process, which you get automatically, when you install using mongodb apt-get/yum packages.