Native and Docker Clusters

Automatic native Clusters

Similarly to how the Mesos framework aranges an ArangoDB cluster in aDC/OS environment for you, arangodb can do this for you in a plainenvironment.

By invoking the first arangodb you launch a primary node. It willbind a network port, and output the commands you need to cut’n’pasteinto the other nodes. Let’s review the process of such a startup onthree hosts named h01, h02, and h03:

  1. arangodb@h01 ~> arangodb --starter.address h01 --starter.port 4000
  2. 2018-11-09T07:18:45-05:00 |INFO| Starting arangodb version 0.13.7, build bdac926 component=arangodb
  3. 2018-11-09T07:18:45-05:00 |INFO| Serving as master with ID '0191e3d2' on h01:4000... component=arangodb
  4. 2018-11-09T07:18:45-05:00 |INFO| Waiting for 3 servers to show up. component=arangodb
  5. 2018-11-09T07:18:45-05:00 |INFO| Use the following commands to start other servers: component=arangodb
  7. arangodb --starter.data-dir=./db2 --starter.join h01:4000
  9. arangodb --starter.data-dir=./db3 --starter.join h01:4000
  11. 2018-11-09T07:18:45-05:00 |INFO| ArangoDB Starter listening on 0.0.0.0:4000 (h01:4000) component=arangodb

So you cut the lines arangodb —data.dir=./db2 —starter.join127.0.0.1 and execute them for the other nodes. If you run it onanother node on your network, replace the —starter.join 127.0.0.1by the public IP of the first host.

  1. arangodbh02 ~> arangodb --starter.data-dir=./db2 --starter.join h01:4000
  2. 2018-11-09T09:04:07-05:00 |INFO| Starting arangodb version 0.13.7, build bdac926 component=arangodb
  3. 2018-11-09T09:04:08-05:00 |INFO| Contacting master http://h01:4000... component=arangodb
  4. 2018-11-09T09:04:08-05:00 |INFO| Waiting for 3 servers to show up... component=arangodb
  5. 2018-11-09T09:04:08-05:00 |INFO| ArangoDB Starter listening on 0.0.0.0:4000 (:4000) component=arangodb
  7. arangodbh03 ~> arangodb --starter.data-dir=./db3 --starter.join h01:4000
  8. 2018-11-09T09:04:07-05:00 |INFO| Starting arangodb version 0.13.7, build bdac926 component=arangodb
  9. 2018-11-09T09:04:08-05:00 |INFO| Contacting master http://h01:4000... component=arangodb
  10. 2018-11-09T09:04:08-05:00 |INFO| Waiting for 3 servers to show up... component=arangodb
  11. 2018-11-09T09:04:08-05:00 |INFO| ArangoDB Starter listening on 0.0.0.0:4000 (:4000) component=arangodb

Once the two other processes joined the cluster, and started their ArangoDB server processes (this may take a while depending on your system), it will inform you where to connect the Cluster from a Browser, shell or your programm:

  1. ...
  2. 2018-11-09T09:10:00-05:00 |INFO| coordinator up and running. component=arangodb

At this point you may access your cluster at either coordinatorendpoint, http://h01:4002/, http://h02:4002/ or http://h03:4002/.

Automatic native local test Clusters

If you only want a local test cluster, you can run a single starter with the —starter.local argument.It will start a 3 “machine” cluster on your local PC.

  1. arangodb --starter.local

Note. A local cluster is intended only for test purposes since a failure of a single PC will bring down the entire cluster.

Automatic Docker Clusters

ArangoDBStarter can also be used to launch clusters based on docker containers.Its a bit more complicated, since you need to provide information about your environment that can’t be autodetected.

In the Docker world you need to take care about where persistent data is stored, since containers are intended to be volatile. We use a volume named arangodb1 here:

  1. docker volume create arangodb1

(You can use any type of docker volume that fits your setup instead.)

We then need to determine the IP of the docker host where youintend to run ArangoDB starter on. Depending on your operating systemexecute ip addr, ifconfig or ipconfig to determine your local ipaddress.

  1. 192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.32

So this example uses the IP 192.168.1.32:

  1. docker run -it --name=adb1 --rm -p 8528:8528 \
  2.     -v arangodb1:/data \
  3.     -v /var/run/docker.sock:/var/run/docker.sock \
  4.     arangodb/arangodb-starter \
  5.     --starter.address=192.168.1.32

It will start the master instance, and command you to start the slave instances:

  1. Unable to find image 'arangodb/arangodb-starter:latest' locally
  2. latest: Pulling from arangodb/arangodb-starter
  3. Digest: sha256:b87d20c0b4757b7daa4cb7a9f55cb130c90a09ddfd0366a91970bcf31a7fd5a4
  4. Status: Downloaded newer image for arangodb/arangodb-starter:latest
  5. 2017/06/12 13:26:14 Starting arangodb version 0.7.1, build f128884
  6. 2017/06/12 13:26:14 Serving as master with ID '46a2b40d' on 192.168.1.32:8528...
  7. 2017/06/12 13:26:14 Waiting for 3 servers to show up.
  8. 2017/06/12 13:26:14 Use the following commands to start other servers:
  10. docker volume create arangodb2 && \
  11.   docker run -it --name=adb2 --rm -p 8533:8528 -v arangodb2:/data \
  12.   -v /var/run/docker.sock:/var/run/docker.sock arangodb/arangodb-starter:0.7 \
  13.   --starter.address=192.168.1.32 --starter.join=192.168.1.32
  15. docker volume create arangodb3 && \
  16.   docker run -it --name=adb3 --rm -p 8538:8528 -v arangodb3:/data \
  17.   -v /var/run/docker.sock:/var/run/docker.sock arangodb/arangodb-starter:0.7 \
  18.   --starter.address=192.168.1.32 --starter.join=192.168.1.32

Once you start the other instances, it will continue like this:

  1. 2017/05/11 09:05:45 Added master 'fc673b3b': 192.168.1.32, portOffset: 0
  2. 2017/05/11 09:05:45 Added new peer 'e98ea757': 192.168.1.32, portOffset: 5
  3. 2017/05/11 09:05:50 Added new peer 'eb01d0ef': 192.168.1.32, portOffset: 10
  4. 2017/05/11 09:05:51 Starting service...
  5. 2017/05/11 09:05:51 Looking for a running instance of agent on port 8531
  6. 2017/05/11 09:05:51 Starting agent on port 8531
  7. 2017/05/11 09:05:52 Looking for a running instance of dbserver on port 8530
  8. 2017/05/11 09:05:52 Starting dbserver on port 8530
  9. 2017/05/11 09:05:53 Looking for a running instance of coordinator on port 8529
  10. 2017/05/11 09:05:53 Starting coordinator on port 8529
  11. 2017/05/11 09:05:58 agent up and running (version 3.2.devel).
  12. 2017/05/11 09:06:15 dbserver up and running (version 3.2.devel).
  13. 2017/05/11 09:06:31 coordinator up and running (version 3.2.devel).

And at least it tells you where you can work with your cluster:

  1. 2017/05/11 09:06:31 Your cluster can now be accessed with a browser at `http://192.168.1.32:8529` or
  2. 2017/05/11 09:06:31 using `arangosh --server.endpoint tcp://192.168.1.32:8529`.

Under the hood

The first arangodb you ran (as shown above) will become the master in your setup, the —starter.join will be the slaves.

The master determines which ArangoDB server processes to launch on which slave, and how they should communicate. It will then launch the server processes and monitor them. Once it has detected that the setup is complete you will get the prompt. The master will save the setup for subsequent starts.

More complicated setup options can be found in ArangoDBStarters Readme.