I have installed redis cluster 3.0.0. But Want to upgrade it to 3.0.7. Can somebody tell me the steps to do it?
I don't want to loose any data. And don't want any downtime either.
Steps I did when upgrading from 2.9.101 to 3.0 release. I hope it will do for upgrading to 3.0.7 too.
Compile 3.0.7 from the source and start several instances with cluster enabled.
Let the 3.0.7 instances replicate the 3.0.0 instances as slave
Connect to each 3.0.7 instance and do a manual failover, then the 3.0.0 masters would become slaves after several seconds.
Wait for your application to connect to the new masters; also check the configuration files, and modify the entries to the new masters on your need
Remove those slaves
UPDATE : Docker approach
As it's probably unable to replacing the binary executable while the process is still alive, you could do it by run some Redis in docker.
First you should install docker on your machine and pull the Redis image, or pull a basic OS image and manually build Redis in it, whatever
Based on this image, you are supposed to
copy your current redis.conf into it
make sure the dir exists in the image (cluster-config-file could be the same for all the containers as they are saved individually in their own fs)
make sure the directory for logfile exists and is not the same as dir (we will later map this directory to the host)
leave port logfile anything you like, as they are specified when a container is started
commit the image as redis-3.0.7
Now launch a containerized Redis. I suppose your logfile is located in /var/log/redis/, this Redis binds :8000, and your config file in the image is /etc/redis/redis.conf
docker run -d --net=host -v /var/log/redis:/var/log/redis \
-p 8000:8000 -t redis-3.0.7 \
/usr/bin/redis-server /etc/redis/redis.conf \
--port 8000 \
--logfile /var/log/redis/redis_8000.log
Now you have a Redis 3.0.7 instance, and are ready to finish the rest steps in the previous part.
Related
I am looking options to install confluent schema registry, is it possible to download and install registry alone and make it work with existing kafka setup ?
Thanks
Assuming you have Zookeeper/Kafka running already, you can easily run Confulent Schema Registry using Docker with running the following command:
docker run -p 8081:8081 -e \
SCHEMA_REGISTRY_KAFKASTORE_CONNECTION_URL=host.docker.internal:2181 \
-e SCHEMA_REGISTRY_HOST_NAME=localhost \
-e SCHEMA_REGISTRY_LISTENERS=http://0.0.0.0:8081 \
-e SCHEMA_REGISTRY_DEBUG=true confluentinc/cp-schema-registry:5.3.2
parameters:
-p 8081:8081 - will open the port 8081 between the container to your machine
SCHEMA_REGISTRY_KAFKASTORE_CONNECTION_URL - is your Zookeeper host and port, I'm using host.docker.internal to resolve local machine that is hosting Zookeeper (outside of the container)
SCHEMA_REGISTRY_HOST_NAME - The hostname advertised in Zookeeper. This is required if if you are running Schema Registry with multiple nodes. Hostname is required because it defaults to the Java canonical hostname for the container, which may not always be resolvable in a Docker environment.
SCHEMA_REGISTRY_LISTENERS - the Schema Registry host and port number to open
SCHEMA_REGISTRY_DEBUG Run in debug mode
note: the script was using the version 5.3.2, make sure this version is aligned with your Kafka version.
Yes you can use your existing Kafka setup, just match to the compatible version of Confluent Platform. Here are the docs on getting started
https://docs.confluent.io/current/schema-registry/docs/intro.html#installation
tl;dr download the platform to pull out the pieces you need or get the docker image and point it at your Kafka cluster.
Redis went quite on me.
user#mycomputer:~$ redis-cli
Could not connect to Redis at 127.0.0.1:6379: Connection refused
I try to restart the service by doing this
sudo /etc/init.d/redis_6379 stop
/var/run/redis/redis.pid exists, process is already running or crashed
But no luck. Logs didn't show an error as well.
Got it fixed by backing up the redis.rdp file mine is located at
/var/lib/redis
check your config file "/etc/redis/redis.conf" for the rdp file's location and do this
sudo mv /var/lib/redis/redis.rdp /var/lib/redis/redis_backup.rdp
Then recreate the the redis.rdp file
sudo touch redis.rdp
Run the redis-server with the conf and it should work
sudo redis-server /etc/redis/redis.conf
Get it fixed in a tidy way: Recreate the the redis.rdp file as suggested here in one of answer, will purge all the cache recorded so far and redis will start up fresh with no cache data.
This is a warning message to notify system crash / improper shutdown: "/var/run/redis/redis.pid exists, process is already running or crashed"
Just delete /var/run/redis/redis.pid file and restart the server again.
Note: You might have lost latest cache changes due to untidy shutdown, which weren't flushed into the disk. This data loss can be minimized using frequent disk flush configuration in redis conf file(in my case it is #/etc/redis/6379.conf)
save 900 1
save 300 10
save 60 10000
Or try AOF persistence, more details [here][1]
Depends on how you installed redis, the pid can be found on /var/run/redis_6379.pid.
What happened is that redis crashed, but the pid is still there. So you just have to delete it.
sudo rm -f /var/run/redis_6379.pid
Then start redis again:
sudo /etc/init.d/redis_6379 start
If you can't find it, I suggest installing redis "more properly". Follow redis quickstart guide in the Installing Redis more properly section.
You can find it here:
https://redis.io/topics/quickstart
Run the redis-server with config.
sudo redis-server redis.conf
I created a Django application which runs inside a Docker container. I needed to create a thread inside the Django application so I used Celery and Redis as the Celery Database.
If I install redis in the docker image (Ubuntu 14.04):
RUN apt-get update && apt-get -y install redis-server
RUN pip install redis
The Redis server is not launched: the Django application throws an exception because the connection is refused on the port 6379. If I manually start Redis, it works.
If I start the Redis server with the following command, it hangs :
RUN redis-server
If I try to tweak the previous line, it does not work either :
RUN nohup redis-server &
So my question is: is there a way to start Redis in background and to make it restart when the Docker container is restarted ?
The Docker "last command" is already used with:
CMD uwsgi --http 0.0.0.0:8000 --module mymodule.wsgi
RUN commands are adding new image layers only. They are not executed during runtime. Only during build time of the image.
Use CMD instead. You can combine multiple commands by externalizing them into a shell script which is invoked by CMD:
CMD start.sh
In the start.sh script you write the following:
#!/bin/bash
nohup redis-server &
uwsgi --http 0.0.0.0:8000 --module mymodule.wsgi
When you run a Docker container, there is always a single top level process. When you fire up your laptop, that top level process is an "init" script, systemd or the like. A docker image has an ENTRYPOINT directive. This is the top level process that runs in your docker container, with anything else you want to run being a child of that. In order to run Django, a Celery Worker, and Redis all inside a single Docker container, you would have to run a process that starts all three of them as child processes. As explained by Milan, you could set up a Supervisor configuration to do it, and launch supervisor as your parent process.
Another option is to actually boot the init system. This will get you very close to what you want since it will basically run things as though you had a full scale virtual machine. However, you lose many of the benefits of containerization by doing that :)
The simplest way altogether is to run several containers using Docker-compose. A container for Django, one for your Celery worker, and another for Redis (and one for your data store as well?) is pretty easy to set up that way. For example...
# docker-compose.yml
web:
image: myapp
command: uwsgi --http 0.0.0.0:8000 --module mymodule.wsgi
links:
- redis
- mysql
celeryd:
image: myapp
command: celery worker -A myapp.celery
links:
- redis
- mysql
redis:
image: redis
mysql:
image: mysql
This would give you four containers for your four top level processes. redis and mysql would be exposed with the dns name "redis" and "mysql" inside your app containers, so instead of pointing at "localhost" you'd point at "redis".
There is a lot of good info on the Docker-compose docs
use supervisord which would control both processes. The conf file might look like this:
...
[program:redis]
command= /usr/bin/redis-server /srv/redis/redis.conf
stdout_logfile=/var/log/supervisor/redis-server.log
stderr_logfile=/var/log/supervisor/redis-server_err.log
autorestart=true
[program:nginx]
command=/usr/sbin/nginx
stdout_events_enabled=true
stderr_events_enabled=true
I have downloaded redis-2.6.16.tar.gz file and i installed sucessfully. After installed i run src/redis-server it worked fine.
But i don't want manually run src/redis-server everytime, rather i want redis-server running as background process continuously.
So far after installed i did following tasks:
1. vim redis.conf and i changed to
# By default Redis does not run as a daemon. Use 'yes' if you need it.
# Note that Redis will write a pid file in /var/run/redis.pid when daemonized.
daemonize yes
But same result i found. What mistake i did?
After redis run in background. I will run juggernaut also as background process with following command.
nohup node server.js
But i am not able to make redis run in background. Please provide some solution.
Since Redis 2.6 it is possible to pass Redis configuration parameters using the command line directly. This is very useful for testing purposes.
redis-server --daemonize yes
Check if the process started or not:
ps aux | grep redis-server
I think the best way is to use Redis' config file:
# By default Redis does not run as a daemon. Use 'yes' if you need it.
# Note that Redis will write a pid file in /var/run/redis.pid when daemonized.
daemonize yes
Set daemonize to yes in the config file. Say the file is ~/.redis/redis.conf, then just run
$ redis-server ~/.redis/redis.conf
And it just works.
Or you can simply run it as src/redis-server redis.conf&
For windows:
Step 1: Install redis as a service
redis-server --server-install
Step 2: Run background
redis-server --server-start
To run redis server in background and ignore output .
nohup redis-server &
To check the server
ps aux | grep redis-server
To Kill server
sudo service redis-server stop
i'm trying to deploy my JSF site in EC2 instances, i'm new with cloud computing.
How do i install the GassFish 3 OpenSource in my EC2 instance ?
Update:
To download use 'curl' command :
curl http://www.java.net/download/jdk6/6u27/promoted/b03/binaries/jdk-6u27-ea-bin-b03-linux-i586-27_may_2011-rpm.bin > java-rpm.bin
or using wget:
wget http://www.java.net/download/jdk6/6u27/promoted/b03/binaries/jdk-6u27-ea-bin-b03-linux-i586-27_may_2011-rpm.bin
Here is what you need to do:
Get an AMI instance launched. Follow this tutorial to install. (Unfortunately, Glassfish installation tutorials are given as YouTube video on their official website!) The Simplest is to start with an existing EBS backed instance. This is how I started.
Now, if you want to kill the instance, it's same as throwing machine out of window. If you want to reuse it later or probably want to make a blue print for many instances that you will be launching in future. You need to bundle it up and register as an image.
If you have EBS backed instance, creating an image out of it is easier than sending an email. All you need to do is to login to your AWS Web Console, select the instance that you wanted to create an AMI of, select Instance Actions > Create Image from menu. Done!
If you have instance storage based AMI. You need to bundle up, and store in your S3 bucket, and register the AMI using, ec2-api-tools and ec2-ami-tools. So, have them installed in your instance and create the image as very neatly explained here.
Now, as far as cost is concerned, refer this. As far as I understand (my clients pay, so I don't really know how much) your running instance is going to cost you some money, even if there is no activity. However, if you make an AMI and store in S3 or in a EBS volume, you will be paying for storage cost.
Hope this explains what you wanted.
First you need to install jdk and then set environment variable JAVA_HOME.
Then follow below commands (Applicable on Amazon Linux EC2 ):
Directory used here is : usr/server
wget http://download.oracle.com/glassfish/4.1.2/release/glassfish-4.1.2.zip
unzip glassfish-4.1.2.zip
mv glassfish4 ../server/
groupadd glassfish-group
useradd -s /bin/bash -g glassfish-group glassfish-user
cd usr/server
chown -Rf glassfish-user.glassfish-group glassfish4
ls -l | grep glassfish
cd glassfish4
cd glassfish/domains
cd glassfish/bin
pwd
cd /etc/init.d/
wget https://geekstarts.info/scripts/glassfish.sh
mv glassfish.sh glassfish
chmod 755 glassfish
ls -l | grep glassfish
cd ~ glassfish/
su vector-user
whoami
pwd
cd glassfish4/bin
ls -l
whoami
./asadmin
change-master-password --savemasterpassword // default is chageit
change-admin-password // default is blank
start-domain
enable-secure-admin
restart-domain
stop-domain