So, I was making an app that needs to use MongoDB transactions. But the Mongoose documentation told me that "MongoDB currently only supports transactions on replica sets, not standalone servers." So I thought I basically need to switch my Standalone MongoDB instance to Replica Set (whatever that means).
The MongoDB documentation gave me the instruction of how to do this with a few steps:
Shutdown the Standalone MongoDB instance
Restart the instance using the --replSet option
mongod --port 27017 --dbpath /var/lib/mongodb --replSet rs0 --bind_ip localhost
Connect the Mongo Shell
Call rs.initiate() inside the Shell
I'm stuck at step 2. All I know, when you want to start using MongoDB, you have to start its daemon first, using sudo systemctl start mongod, and then start using it by connecting your app. but that step told me to use mongod command to start the Mongod daemon, instead of systemctl. I tried the command but got the following error:
DBException in initAndListen, terminating","attr":{"error":"IllegalOperation: Attempted to create a lock file on a read-only directory: /var/lib/mongodb"}}
At first, I thought it was some kind of a privilege issue, so I ran it again with sudo but then it ended up destroying my entire database and prevented me from starting the MongoDB the "normal way" with giving me errors that I cannot remember.
I just reinstalled the whole MongoDB to get it back to work fine. Now I'm at the same place as yesterday, unable to convert to replica set, only now my entire database is gone. What do I do to enable it?
When running the mongod as a service, use /etc/monogd.conf to set the configuration. Note that the location or name of this file might have been changed in the mongod.service file in your system.
See replication options for how to set that in the file.
Related
I have 3 servers running a MongoDB replica set.
I currently start the node like this after restarting a server:
mongod --replSet "name_of_replicaset" --bind_ip localhost,this_server_hostname_in_host_file --fork --syslog --auth --keyFile "path_to_file"
The problem is that I have to do this every single time I restart a server.
I've checked online and the official documentation for MongoDB but I cannot find a way to make the server startup the node by itself.
Is there a way to have the server startup the node after it restarting?
You can do this using systemctl.
Create a service for this and enable the same via systemctl enable command. It will automatically start once you restart the server.
I have mongodb set to autoload in systemctl. But when I make too many requests to it, it crashes with the mark failed. how can I make autorestart mongodb so that even after an error it starts up and works again, now I have to manually prescribe systemctl start mongod
As #papey say, there is need to check Restart=always field in this file /lib/systemd/system/mongod.service
I'm using MongoDB, Node.js and Ubuntu 16.04 OS.
I set up MongoDB database from mongo CLI. I also communicated with it using node.js's mongodb library.
I thought I should start the database first (and start listening on the port) with mongod command.
But now I didn't start the database with mongod and still my communication from node.js towards database works fine.
Should mongod be run prior to communication with database, or is mongod process still alive from restart (I cannot find it listed in processes), or maybe my node.js code stores data in local variables that I haven't notice?
check on your ubuntu:
ps aux | grep mongod
if you see a process then it's running.
You can also write: top
With top you will see the current status of your system along with all the processes running.
With ps au you only see all process that are not attached to your TTY
Mongo shell not connecting
I have dedicated centos server
I installed mongodb as a service in my server from here
I even restarted server after installing mongodb
When i tries to run mongo shell it always saying
Error: couldn't connect to server 127.0.0.1:27017 (127.0.0.1), connection attempt failed at src/mongo/shell/mongo.js:146
I tried to remove that mongod.lock but no joy
I dont understand why this happens, because when mongod starts as a service it creates a log in system and telling that it has opened the door to listen incoming connection on port 27017. But it is throwing error while i connecting to mongo shell.
Please see this steps i have used --> click here
Well i wants to use this mongo service first of all at local based with only 127.0.0.1 access. I can change that in mongod.conf file afterward.
Be sure with iptables, Firwalll causing this kind of issue on live server.
So please do this if you facing this kind of same issue,
Do iptables off for a moment
# /etc/init.d/iptables stop
# sudo service mongod start
# mongo
Here what i wanted to see finally,
MongoDB shell version: 2.6.7
connecting to: test
Welcome to the MongoDB shell.
For interactive help, type "help".
For more comprehensive documentation, see
http://docs.mongodb.org/
Questions? Try the support group
http://groups.google.com/group/mongodb-user
show dbs
admin (empty)
local 0.078GB
Thanks guys who considered my question and looking in it.
Thanks a lot.
After simply installing MongoDB and creating \data\db within the MongoDB folder, I proceeded to run mongod.exe --dbpath C:\MongoDB\data\db. It runs a bunch of initandlisten code and then when it waits for connections on port 27017 it hangs and writes out mem res:47 virt:171 mapped:80 connections:0. I am very new to Mongo and haven't found a definitive answer on why this is hanging and how to fix it.
If you want to run the mongod.exe process as a service under Windows (to avoid it taking up a command prompt) you should following these directions for MongoDB 2.6.0 (2.6.0 has a bug with the normal approach to configuring MongoDB as a service).
There is a known issue for MongoDB 2.6.0, SERVER-13515, which prevents
the use of the instructions in this section. For MongoDB 2.6.0, use
Manually Create a Windows Service for MongoDB to create a Windows
Service for MongoDB instead.
http://docs.mongodb.org/manual/tutorial/install-mongodb-on-windows/#manually-create-windows-service
For MongoDB versions 2.6.1 and later follow the normal directions:
http://docs.mongodb.org/manual/tutorial/install-mongodb-on-windows/#configure-a-windows-service-for-mongodb
Mongo waiting on 27017 even after reinstall
The waiting for connections message in the console output indicates that the mongod.exe process is running successfully.
After you install MongoDB, you need to connect to MongoDB through mongo.exe shell using another command prompt.
As soon as you are done with that, the waiting message in first console would change to connection accepted.