Is there a way to restart the Rails app (e.g. when you've changed a plugin/config file) while Mongrel is running. Or alternatively quickly restart Mongrel. Mongrel gives these hints that you can but how do you do it?
** Signals ready. TERM => stop. USR2 => restart. INT => stop (no restart).
** Rails signals registered. HUP => reload (without restart). It might not work well.
You can add the -c option if the config for your app's cluster is elsewhere:
mongrel_rails cluster::restart -c /path/to/config
1st discover the current mongrel pid path with something like:
>ps axf | fgrep mongrel
you will see a process line like:
ruby /usr/lib64/ruby/gems/1.8/gems/swiftiply-0.6.1.1/bin/mongrel_rails start -p 3000 -a 0.0.0.0 -e development -P /home/xxyyzz/rails/myappname/tmp/pids/mongrel.pid -d
Take the '-P /home/xxyyzz/rails/myappname/tmp/pids/mongrel.pid' part and use it like this:
>mongrel_rails restart -P /home/xxyyzz/rails/myappname/tmp/pids/mongrel.pid
Sending USR2 to Mongrel at PID 18481...Done.
I use this to recover from the dreaded "Broken pipe" to MySQL problem.
in your rails home directory
mongrel_rails cluster::restart
For example,
killall -USR2 mongrel_rails
Related
I have started a rails server puma by using the following command.
nohup rails server &
its output was [2] 22481 along with the following:
nohup: ignoring input and appending output to 'nohup.out'
But now I have forget the returned process id, so how can I detect the process id so as to delete the process on aws.
To kill whatever is on port 3000 (webrick server default port), type this below command to get process id for 3000 port:
$ lsof -wni tcp:3000
Then, use process id (PID) to kill the process:
$ kill -9 PID
Rails server process pid can be found in this directory:
-> tmp/pids/server.pid
then,
Kill -9 pid
command
ps -ef
return the full output list of processes in which one of the list item is as:
ec2-user 12992 1 0 Dec20 ? 00:00:57 puma 3.12.0 (tcp://0.0.0.0:3000) [tukatech_garmentstore_live]
so force killed the process by.
kill -9 12992
did the job
ps aux|grep 3000
This will give you rails server id running on port 3000
I have made some changes to various files, and need to shut down and then restart the server to see them. I am using the Cloud9 railstutorial environment. But I keep getting the same error - "A server is already running". Please see below:
darrenbrett:~/workspace/sample_app (filling-in-layout) $ rails server -b $IP -p $PORT
=> Booting WEBrick
=> Rails 4.2.2 application starting in development on http://0.0.0.0:8080
=> Run `rails server -h` for more startup options
=> Ctrl-C to shutdown server
A server is already running. Check /home/ubuntu/workspace/sample_app/tmp/pids/server.pid.
Exiting
darrenbrett:~/workspace/sample_app (filling-in-layout) $
Find out the process id (PID) first:
$ lsof -wni tcp:8080
This will give you something like this:
$ lsof -wni tcp:8080
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
ruby 59656 rislam 14u IPv6 0xa86b8563672ef037 0t0 TCP [::1]:http-alt (LISTEN)
Then, kill the process with PID = 59656 (for example, it will be different for you):
$ kill -9 59656
This should solve your problem.
You can also use the following command to kill all running apps that has rails in the name:
killall -9 rails
Sometimes, this is very effective when the first command does not do the trick.
It sounds like you either have an orphaned server process running, or you have multiple applications in the same environment and you're running the server for another one and it's bound to the same port. I'm guessing the former.
Run ps -fe | grep rails. You should see something like 501 35861 2428 0 1:55PM ttys012 0:04.00 /your_file_path/ruby bin/rails server
Grab the process id (in the case of the example, it's 35861), and run kill -9 35861. Then try to start your server again.
The easiest way I found to kill that server is to click on the suggested file in the line:
A server is already running. Check /home/ubuntu/workspace/sample_app/tmp/pids/server.pid
That opens the file containing a number, the process id you're looking for.
Example
43029
In the terminal window use "kill" via that same process id and restart the server.
kill -15 43029
rails server -b $IP -p $PORT
I'm sending a USR2 signal to the master process in order to achieve zero downtime deploy with unicorn. After the old master is dead, I'm getting the following error:
adding listener failed addr=/path/to/unix_socket (in use)
unicorn-4.3.1/lib/unicorn/socket_helper.rb:140:in `initialize':
Address already in use - /path/to/unix_socket (Errno::EADDRINUSE)
The old master is killed in the before_fork block on the unicorn.rb config file. The process is started via upstart without the daemon (-D) option.
Any Ideia on what's going on?
Well, turns out you have to run in daemonized mode (-D) if you want to be able to do zero downtime deployment. I changed a few things in my upstart script and now it works fine:
setuid username
pre-start exec unicorn_rails -E production -c /path/to/app/config/unicorn.rb -D
post-stop exec kill cat `/path/to/app/tmp/pids/unicorn.pid`
respawn
I have a thin cluster set up to start 3 servers:
/etc/thin/myapp.yml
...
wait: 30
servers: 3
daemonize: true
...
and the I use thin restart -C /etc/thin/myapp.yml to restart. However, I would like to restart each server at a time, to reduce downtime.
Is there a way to restart each server by pid number or location for example?
There is something better for you
try option: --onebyone
you may also add the following line to your config file
onebyone: true
afterwards you able to restart you thin cluster without any downtime.
I know the question has been answered, but I'd like to add the -o option to the mix.
So
thin restart -C /etc/thin/myapp.yml -o 3000
Will only start the server running on port 3000. If let's say you have two other servers running on 3001 and 3002, they'll be left untouched.
-o works with start and stop commands too.
What is the best way to stop a Unicorn Server process from running? Whenever I try to stop it using kill -p 90234 it does not work. It is most likely something I am doing wrong.
Thanks.
Have a look at the Unicorn SIGNALS page. If the master is behaving correctly and you just want to turn it off, you should send a QUIT signal:
kill -QUIT 1234 # where 1234 is the real process id, of course
That gracefully stops all the workers, letting them finish any requests that they're in the middle of serving.
I use this:
ps aux | grep 'unicorn' | awk '{print $2}' | xargs sudo kill -9
I just looked back at this two months later. This is craziness, and don't use this if you have more than one Unicorn master and you only want to kill one of them.
Interesting that no-one considered the pid file that unicorn creates? My usual config puts it in ./tmp/unicorn.pid, so perhaps the safest way is
kill -QUIT `cat tmp/unicorn.pid`
and the pid file is then properly deleted by the departing process. I always put the pid file in the same relative place so I guess I could alias that for convenience, although when I am developing I don't usually daemonize unicorn.
I would probably go with:
sudo pkill unicorn_rails
ps aux | grep unicorn
#=> root 4393 2.0 0.9 65448 20764 ? S 20:06 0:35 unicorn_rails m
kill 4393
Ultimately, the key is the following line which targets the master unicorn process and kills it
kill $(ps aux | grep '[u]nicorn_rails master' | awk '{print $2}')
Usually I'm lazy and I just kill by name:
$ killall processname
Simple Things There - In Terminal type "ps" and have a look for the Master Unicorn Process. Copy the PID of it and then type "kill −9 90234" (where 90234 is PID of master unicorn process). After that worker process should disappear itself.
for those using chef and seeing that none of the above works (because the processes are respawned as soon as you kill them):
sudo sv stop APP_NAME
sv is the control for runit.
To quit a specific Unicorn server you can use something like the following:
pkill -QUIT --pidfile /path/to/app/shared/tmp/pids/unicorn.pid
This way you can selectively kill any process and you don't have to use shell evaluation/expansion which may not be available.