Server remediation as a service
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Warehouse scale server repair, more benign than borg.

Bynar is an open source system for automating server maintenance across the datacenter. Bynar builds upon many years of experience automating the drudgery of server repair. The goal is to have the datacenter maintain itself. Large clusters these days require lots of maintenance. Cassandra, Ceph, Gluster, Hadoop and others all require quick replacement of server parts as they break down or the cluster can become degraded. As your cluster grows, you generally need to have more people to maintain them. Bynar hopes to break this cycle and free up your time so that your clusters can scale to ever greater sizes without requiring more people to maintain them.

The project is divided into different binaries that all communicate over protobuf:

  1. disk-manager: This program handles adding and the removal of disks from a server
  2. dead-disk-detector: This program handles detection of failed hard drives, files a ticket for a datacenter technician to replace the drive, waits for the resolution of the ticket and then makes an API call to disk-manager to add the new disk back into the server.
  3. bynar-client: Enables you to manually make API calls against disk-manager and dead-disk-detector

To start using Bynar


  1. Create your configuration file. The utility takes json config information. Edit the /etc/bynar/bynar.json file to configure it. The slack_* fields are optional. They will allow Bynar to send alerts to a channel while it's performing maintenance. JIRA is the only currently supported back end ticketing system. A plugin system allows for more back end support.
    An optional proxy field can be configured to send JIRA REST API requests through. For extra security we highly recommend that you enable the vault integration. The disk-manager sits on a port and if an attacker gains access to it they can quickly wipe out your disks. If you don't wish to enable vault integration set the disk-manager up to only listen on a loopback port. Fields for this file are:
 "db_location": "/etc/bynar/disks.sqlite3",
 "proxy": "https://my.proxy",
 "manager_host": "localhost",
 "manager_port": 5555,
 "slack_webhook": "",
 "slack_channel": "#my-channel",
 "slack_botname": "my-bot",
 "jira_user": "test_user",
 "jira_password": "user_password",
 "jira_host": "",
 "jira_issue_type": "3",
 "jira_priority": "4",
 "jira_project_id": "MyProject",
 "jira_ticket_assignee": "assignee_username",
 "vault_endpoint": "",
 "vault_token": "token_98706420"

Disk Manager

This binary handles adding and removing disks from a server. It uses protobuf serialization to allow RPC usage. Please check the api crate for more information or the bynar-client.


  1. Create your configuration file. The utility takes json config /etc/bynar/disk-manager.json file. This file should be deployed
    when the Bynar package is installed. The vault_* options are optional but recommended. When enabled the disk-manager upon starting will save the generated public key to vault under /bynar/{hostname}.pem. Any clients wanting to connect to it will need to contact vault first. If vault is not enabled it will save the public key to /etc/bynar/.
  "backend": "ceph",
  "vault_endpoint": "https://my_vault:8888",
  "vault_token": "token_98706420"

Bynar that runs on Ceph, should have a ceph.json file to describe it. This tells where to look for ceph configuration, user details etc. /etc/bynar/ceph.json file:

  "config_file": "/etc/ceph/ceph.conf",
  "user_id": "admin"

Directory layout:

  1. Top level is the dead disk detector
  2. api is the protobuf api create
  3. disk-manager is the service that handles the adding and removal of disks

Launch the program

  1. After building Bynar from source or downloading prebuilt packages launch the disk-manager, dead-disk-detector service on every server you want maintained.

To start developing Bynar

This community repository hosts all information about building Bynar from source, how to contribute code and documentation, who to contact about what, etc.

If you want to build Bynar:

You have a working [Rust environment].
$ curl -sSf | sh
$ rustup override set nightly
$ cargo build --release

Dependencies for Ubuntu 18.04:

  1. libzmq3-dev 4.1 or higher
  2. libprotobuf-dev 2.5 or higher
  3. librados2 # ceph jewel or higher
  4. libatasmart-dev
  5. libssl-dev
  6. libblkid-dev
  7. libsqlite3-dev
  8. libudev # for building
  9. librados-dev # for building Installing Bynar under Ubuntu 18.04:
  10. add deb ./ to /etc/apt/sources.list
  11. wget -O- | sudo apt-key add
  12. enable universe: deb bionic universe
  13. apt update && apt install libzmq5

Hard Drive Workflow

Hard drives die all the time as part of the regular cycle of things in servers. Bynar can nearly completely automate that maintenance except for the actual replacing of the drive. The typical workflow by a human would look something like this:

  1. Receive an alert about a drive failing
  2. SSH over to the server to investigate. Try to rule out obvious things
  3. Conclude drive is dead and file a support ticket with the datacenter tech to remove it
    • Or file a ticket with HP/Dell/Cisco/Etc to replace the drive
  4. Depending on the software running on top of this drive I may have to:
    • Inform the cluster that the drive is dead
    • Rebalance the data in the cluster
  5. Wait for a replacement
  6. After the drive is replaced inform the clusters that the drive is now back in service and rebalance the data back onto the drive.

So how can Bynar help? Well it can handle steps 1,2,3,4 and 6. Nearly everything! While it is replacing your drives it can also inform you over slack or other channels to keep you in the loop. The time saved here multplies with each piece of hardware replaced and now you can focus your time and energy on other things. It's a positive snowball effect!


Note that root permissions are required for integration testing. The reason is that the test functions will attempt to create loopback devices, mount them, check their filesystems etc and all that requires root. The nightly compiler is also required for testing because mocktopus makes use of features that haven't landed in stable yet. Run: sudo ~/.cargo/bin/cargo test -- --nocapture to test.

Support and Contributions

If you need support, start by checking the issues page. If that doesn't answer your questions, or if you think you found a bug, please file an issue.

That said, if you have questions, reach out to us communication.

Want to contribute to Bynar? Awesome! Check out the contributing guide.