Znappy

Znappy is a distributed, decentralized agent for creating snapshots.

The currenty drivers are based on ZFS and MySQL, using ZFS to create snapshots of the MySQL data. However, due to it's modulair/event-driven design, this can easily be extended.

Znappy works by storing information in Consul and using the locking mechanism provided by Consul to desync the creation of states/snapshots.

Installation

For debian, znappy package can be build using:

fpm \
    -s python \
    -t deb \
    --no-python-fix-dependencies \
    --no-python-fix-name \
    --deb-upstart  etc/init/znappy-daemon \
    setup.py

Configuration

For the agent to work, it expects 2 configuration files in /etc/znappy

The cluster.yaml file will not be used by the agent, but is needed in the console to create the cluster configuration in Consul, this can be triggered by znappy config update (see znappy config --help)

client.yaml

---
cluster: foo
log-level: WARN
consul-host: localhost
consul-port: 8500

and..

cluster.yaml

---
config-version: 1
drivers:
  znappy.backend.mysql:
    mycnf_path: /root/.my.cnf
    mycnf_section: client
    failover_creds: /etc/mysql/failover.cnf
  znappy.snapshot.zfs:
    filesystem: data/mysql
    # Dataset properties to copy when recoverying snapshots
    properties:
      - atime
      - compression
      - mountpoint
      - primarycache
      - recordsize
      - sync
  znappy.monitor.snapshot: {}
snapshot:
  min_age: 900
  rotate: 48