How to stop mongod after "unkown instance" error - mongodb

After running two mongodb instance, I can't stop mongod service. After executing:
$ sudo service mongod stop
Stop: Unkown instance
I know that this question have been asked but they are looking for how to avoid this error and I am looking for how to actually stop the mongod service after getting this error...

Running sudo service mongod start twice doesn't start mongo twice. It should be an idempotent operation meaning it only has an effect the first time if mongo wasn't running. Any attempts to start it afterwards will do nothing.
Your message of Stop: Unkown instance will mean that it couldn't find any running Mongo processes to stop.
To verify Mongo isn't running, try running
sudo ps aux | grep -v grep | grep mongo
If that returns nothing, then you don't have any mongo processes running.

I usually just kill the process. Works every time.
killall -9 mongod

Related

Cannot start Mongo DB server on MAC

I sometimes can start the mongodb server and sometimes I cannot. What is the real problem with my mongodb server. I am using Mac and I am getting this problem for the first time.
I tried to kill the mongodb process but it didn't help me.
Any possible solutions would be highly appreciated.
The error I am getting is below.
For killing the process, I tried to kill 27017 and it says no process found.
I think you are confusing port and PID. When you kill 27017, you send the SIGKILL signal to a process whose PID is 27017. However, unless there is a coincidence, mongod does not need to have that PID. 27017 is the default port for mongod instances.
To kill it properly do the following:
ps -edf | grep mongod --> get the PID of the mongod process
Then:
kill -SIGKILL <pid>
Then start it again.

Mongodb How can I stop shutdown one of instances

I'm a newbie to Mongodb. I installed Mongodb 3.4 and setup two config files each config has different port and share a same ip address. How can I shut down instance in mongoA.conf file. Try to use command "sudo service mongod stop" But it doesn't know which config file to stop the service. Thanks in advance
start two instances Mongodb config files:
mongod --config /etc/mongoA.conf
mongod --config /etc/mongoB.conf
You can find PID of mongod port. Then kill process on that PID.
To find all PID mongod, type:
# ps -aux | grep mongod
You will see on console:
root 28035 0.9 18.5 5319648 2992608 ? Sl Apr06 1493:14 mongod --config /etc/mongoA.conf
Then kill process on this PID:
# sudo kill -9 NUMBER_PID
On above example, NUMBER_PID is 28035.
On OSX ps -alx will give the same list of processes.
If you allow kill to send the default TERM signal by not using -9 explicitly it will allow the database to catch the TERM signal and shutdown cleanly.

Clean shutdown of the mongod process

My mongodb run under Linux 6. I use the command db.shutdownServer() to close the database but the mongod process does not stop.
Stopping mongo directly with service mongod stop do a clean shutdown?
Thanks for your help
Proper ways to shutdown mongod is described in the documentation. They are:
Use shutdownServer()
From the mongo shell
use admin
db.shutdownServer()
Use --shutdown
From the Linux command line
mongod --shutdown
Use CTRL-C
When running the mongod instance in interactive mode, issue Control-C
Use kill
From the Linux command line
kill mongoProcessID
kill -2 mongodProcessID
So you need to figure out how /etc/init.d/mongodb stop actually stops the process on your Linux distribution. For example, on Debian it uses the wrapper which behaves similar to killall which is a proper method.
As per the documentation of mongodb, mongod --shutdown will work on linux system, but, on Mac, the --shutdown switch is not recognised. However, per the documentation, Ctrl+C will cleanly shutdown the db server. When you do a Ctrl+C on the same terminal where the db server is running, it initiates a dozen or so signalProcessingThread which indicates that the shutdown is proper and smooth. At the end, you can see that the process exits with code:0. Per the convention, Ctrl+C is awkward, but is clean, although not seemingly graceful.

How do I make it so Mongo runs automatically all the time on my Azure server?

I have two Azure virtual machines. On one I have a Mongo server, on the other I just have a service I created which listens to Twitters streaming API and filters tweets.
Neither of these two services work unless I manually activate them and keep my console window open. For example, to run Mongo I need to ssh into my virtual machine and type: mongod --config /etc/mongod.conf. This starts the Mongo server successfully, but if at anytime I close my browser the service stops.
I believe the reason this is occurring is because when I login the system is allocating me a process by which I can navigate around the system and perform commands. When I type mongod --config /etc/mongod.conf I believe I am using that process to run Mongo. I am not sure how to make Mongo run without doing this though.
How do I make it so Mongo runs automatically all the time on my Azure server?
EDIT:
I tried running Mongo as a daemon but I receive an error:
$ mongod --fork --logpath /var/log/mongodb.log
>>>about to fork child process, waiting until server is ready for connections.
>>>forked process: 63470
>>>ERROR: child process failed, exited with error number 1
This issue has nothing to do with Azure; it's all about how you install MongoDB.
If you install mongodb as a service, via apt-get (or whatever other means your version of linux requires), then it will run independent of you being logged in. You shouldn't be running an always-on service through your command shell.
Here are instructions for installing under Ubuntu. You'll see that, once you set up the prerequisite public key and list file, you then run:
sudo apt-get install -y mongodb-org
You can then start and stop the service via
sudo service mongod start
and
sudo service mongod stop
You can enable mongo to autostart on boot by typing this command in your console:
sudo systemctl enable mongod
Then test it by this command:
sudo service mongod status

How to stop mongo DB in one command

I need to be able to start/stop MongoDB on the cli. It is quite simple to start:
./mongod
But to stop mongo DB, I need to run open mongo shell first and then type two commands:
$ ./mongo
use admin
db.shutdownServer()
So I don't know how to stop mongo DB in one line. Any help?
Starting and Stopping MongoDB is covered in the MongoDB manual. It explains the various options of stopping MongoDB through the shell, cli, drivers etc. It also details the risks of incorrectly stopping MongoDB (such as data corruption) and talks about the different kill signals.
Additionally, if you have installed MongoDB using a package manager for Ubuntu or Debian then you can stop mongodb (currently mongod in ubuntu) as follows:
Upstart: sudo service mongod stop
Sysvinit: sudo /etc/init.d/mongod stop
Or on Mac OS X
Find PID of mongod process using $ top
Kill the process by $ kill <PID> (the Mongo docs have more info on this)
Or on Red Hat based systems:
service mongod stop
Or on Windows if you have installed as a service named MongoDB:
net stop MongoDB
And if not installed as a service (as of Windows 7+) you can run:
taskkill /f /im mongod.exe
To learn more about the problems of an unclean shutdown, how to best avoid such a scenario and what to do in the event of an unclean shutdown, please see: Recover Data after an Unexpected Shutdown.
If you literally want a one line equivalent to the commands in your original question, you could alias:
mongo --eval "db.getSiblingDB('admin').shutdownServer()"
Mark's answer on starting and stopping MongoDB via services is the more typical (and recommended) administrative approach.
mongod --dbpath /path/to/your/db --shutdown
More info at official: http://docs.mongodb.org/manual/tutorial/manage-mongodb-processes/
If the server is running as the foreground process in a terminal, this can be done by pressing
Ctrl-C
Another way to cleanly shut down a running server is to use the shutdown command,
> use admin
> db.shutdownServer();
Otherwise, a command like kill can be used to send
the signal. If mongod has 10014 as its PID, the command would be
kill -2 10014
I followed the official MongoDB documentation for stopping with signals. One of the following commands can be used (PID represents the Process ID of the mongod process):
kill PID
which sends signal 15 (SIGTERM), or
kill -2 PID
which sends signal 2 (SIGINT).
Warning from MongoDB documentation:
Never use kill -9 (i.e. SIGKILL) to terminate a mongod instance.
If you have more than one instance running or you don't care about the PID, you could use pkill to send the signal to all running mongod processes:
pkill mongod
or
pkill -2 mongod
or, much more safer, only to the processes belonging to you:
pkill -U $USER mongod
or
pkill -2 -U $USER mongod
NOTE:
If the DB is running as another user, but you have administrative rights, you have invoke the above commands with sudo, in order to run them. E.g.:
sudo pkill mongod
sudo pkill -2 mongod
PS
Note: I resorted to using signals because mongod --shutdown, although mentioned in the current MongoDB documentation, did not work on my machine (macOS, mongodb v3.4.10, installed with homebrew):
Error parsing command line: unrecognised option '--shutdown'
Update 2022-05-10
meanwhile option --shutdown is marked in the documentation as "Supported on Linux only".
PPS
(macOS specific) Before anyone wonders: no, I could not stop it with command
brew services stop mongodb
because I did not start it with
brew services start mongodb
I had started mongod with a custom command line :-)
Use mongod --shutdown
According to the official doc : manage-mongodb-processes/
:D
create a file called mongostop.bat
save the following code in it
mongo admin --eval "db.shutdownServer()"
run the file mongostop.bat and you successfully have mongo stopped
My special case is:
previously start mongod by:
sudo -u mongod mongod -f /etc/mongod.conf
now, want to stop mongod.
and refer official doc Stop mongod Processes, has tried:
(1) shutdownServer but failed:
> use admin
switched to db admin
> db.shutdownServer()
2019-03-06T14:13:15.334+0800 E QUERY [thread1] Error: shutdownServer failed: {
"ok" : 0,
"errmsg" : "shutdown must run from localhost when running db without auth",
"code" : 13
} :
_getErrorWithCode#src/mongo/shell/utils.js:25:13
DB.prototype.shutdownServer#src/mongo/shell/db.js:302:1
#(shell):1:1
(2) --shutdown still failed:
# mongod --shutdown
There doesn't seem to be a server running with dbpath: /data/db
(3) previous start command adding --shutdown:
sudo -u mongod mongod -f /etc/mongod.conf --shutdown
killing process with pid: 30213
failed to kill process: errno:1 Operation not permitted
(4) use service to stop:
service mongod stop
and
service mongod status
show expected Active: inactive (dead) but mongod actually still running, for can see process from ps:
# ps -edaf | grep mongo | grep -v grep
root 30213 1 0 Feb04 ? 03:33:22 mongod --port PORT --dbpath=/var/lib/mongo
and finally, really stop mongod by:
# sudo mongod -f /etc/mongod.conf --shutdown
killing process with pid: 30213
until now, root cause: still unknown ...
hope above solution is useful for your.
Building on the answer from stennie:
mongo --eval "db.getSiblingDB('admin').shutdownServer();quit()"
I found that mongo was trying to reconnect to the db after the server shut down, which would cause a delay and error messages. Adding quit() after shutdown speeds it up and reduces the messages, but there is still one.
I also want to add context - I'm starting and stopping mongod as part of test cases for other code, so registering as a service does not fit the use case. I am hoping to end up with something that runs on all platforms (this tested in windows right now). I'm using mongod 3.6.9
One liners to start or stop mongodb service using command line;
To start the service use: NET START MONGODB
To stop the service use: NET STOP MONGODB
I use this myself, it does work.
From the given commands I think you're on Linux.
Start MongoDB:
$ sudo service mongod start
mongod start/running, process XXXXX
Check the Status:
$ sudo service mongod status
mongod start/running, process XXXXX
Stop MongoDB:
$ sudo service mongod stop
mongod stop/waiting
Using homebrew (recommended way):
To start:
brew services start mongodb-community
To stop:
brew services stop mongodb-community
I simply did:
quit();
Please note I'm using mongo 3.0.
Mongo
in the terminal window on your mac, press control+c
I use this startup script on Ubuntu.
#!/bin/sh
### BEGIN INIT INFO
# Provides: mongodb
# Required-Sart:
# Required-Stop:
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: mongodb
# Description: mongo db server
### END INIT INFO
. /lib/lsb/init-functions
PROGRAM=/opt/mongo/bin/mongod
MONGOPID=`ps -ef | grep 'mongod' | grep -v grep | awk '{print $2}'`
test -x $PROGRAM || exit 0
case "$1" in
start)
log_begin_msg "Starting MongoDB server"
ulimit -v unlimited.
ulimit -n 100000
/opt/mongo/bin/mongod --fork --quiet --dbpath /data/db --bind_ip 127.0.0.1 --rest --config /etc/mongod.conf.
log_end_msg 0
;;
stop)
log_begin_msg "Stopping MongoDB server"
if [ ! -z "$MONGOPID" ]; then
kill -15 $MONGOPID
fi
log_end_msg 0
;;
status)
;;
*)
log_success_msg "Usage: /etc/init.d/mongodb {start|stop|status}"
exit 1
esac
exit 0
Windows
In PowerShell, it's: Stop-Service MongoDB
Then to start it again: Start-Service MongoDB
To verify whether it's started, run: net start | findstr MongoDB.
Note: Above assumes MongoDB is registered as a service.
Kindly take advantage of the Task Manager provided by your OS for a quick and easy solution. Below is the screengrab from/for Windows 10. Right-click on the highlighted process and select stop. Select start, if already stopped.
Please Note: Internally the commands are doing the same thing which you have to do manually using a GUI (Task Manager), provided by Windows/your OS. Though, this approach to be used for study/practice purpose to get started and you won't be blocked due to this.
To start
sudo /etc/init.d/mongodb start
To stop
sudo /etc/init.d/mongodb stop
CTRL + C
on the windows command line