* Add methods for probing table schema, and linking tables to pools * Bundled online_schema_change plugin, a wrapper around Percona's pt-online-schema-change tool that allows clean management of ALTER TABLE, especially on shards * Bundled capacity_plan plugin, which can track and generate reports on data set growth rate, hardware accounting, and more * Bundled upgrade_helper plugin, which adds Jetpants commands for managing a major MySQL upgrade and interacting with a few more tools from Percona Toolkit * Cleaned up spare node related logic, and made it easier for custom plugins to implement new validation rules around spares * Add an example script that uses Jetpants as a library. This script can be used to count all rows in your database topology, quickly and concurrently, via doing chunked count queries on standby slaves * Several minor bugfixes and internal code refactoring
… queries on standby slaves
…split logic. We cannot currently grab separate spare counts by role reliably because there is not a correct node to use for the :like parameter before the shard has been created.
…ange is made really), we need to reset its validation error list
…slaves that are no longer slaving
In "jetpants shard_split" and "jetpants shard_cutover", when we claim spares to make slaves for the new shard(s), supply a :like param of the new shard's master. This way, a custom plugin could implemented special logic to assist with a MySQL upgrade if desired -- ie, it could make :role => :master always use a new version box (regardless of :like), so that any newly-created shards will be created using the newer version of MySQL from the start. Combined with the change in this commit, in this situation the shard will now also correctly get new-version slaves matching the master.