This commit refactors the anti-entropy system to fetch data from
all replicated blocks and only set/clear bits which deviate from
the consensus between all blocks.
An example of this is if 3 nodes had the following bits set for
a single bitmap:
Node A: 1 2 3
Node B: 2 4
Node C: 1 2 4
Then only bits which are set on a majority will be set. In this
case bits 1, 2, & 4 are set but 3 only exists on a single node.
The node performing the merge would then determine the following
set/clear diffs for each node:
Node A: clear(3), set(4)
Node B: set(1)
Node C: none
Once the merge is performed and all nodes receive their diff
instructions then the nodes will be in sync:
Node A: 1 2 4
Node B: 1 2 4
Node C: 1 2 4
There still exists situations where bits can be reset. If Node A
is up and Node B & C are down then Node A's bits will be reset
once B & C come back online. We should add write consistency
settings for incoming writes so that we can ensure that a quorum
is written to before returning a success. This is outside the
scope of this commit though.
This commit re-adds the `testdata` folder that godeps strips and
also updates the `Makefile` to add a `vendor` target that will
handle this in the future.
This commit adds a simple benchmarking utility to the `pilosactl`
binary. It currently only supports individual `SetBit()` commands
but it's a good start towards making a generic benchmarking
framework at the integration level.
The subcommands and usage/help messages were also cleaned up to
output correctly.
This commit adds a new HTTP handler to return a list of all databases
and frames in the index:
GET /schema
This returns JSON in the following format:
{
"dbs":[
{
"name":"d0",
"frames":[
{"name":"f0"},
{"name":"f1"}
]
}
]
}
Fixes#61
This commit changes the backup format of a fragment from a
simple file stream to a tar archive which combines the data file
and the cache file.
Fixes#63
This commit adds an endpoint to restore an entire frame from
another cluster. Multiple hosts can use this endpoint to copy
and rebalance a cluster to a new cluster.
This commit changes the `pql.Query` so that it can accept one or more
top-level calls instead of only one.
The query request format change because a query with a single call is
still valid. However, the result format now returns a `results` field
that has one result for each top-level call. The `profiles` field is
still the same, however, it combines all profiles from all bitmap
responses into one return so that there's not duplicate attributes.
Fixes#59
This commit adds two commands:
pilosactl backup
pilosactl restore
The `Client` implementations have also been added to support these
commands:
func (c *Client) BackupTo(w io.Writer, db, frame string) error
func (c *Client) RestoreFrom(r io.Reader, db, frame string) error
Backups occur on a per-frame basis and all slices from the cluster
are packed into a single tar file. The backup tool attempts to
read from owner nodes in a random order and will retry against
the next owner if one fails.
During restore, the slices are restored to all owner nodes. This
allows users to backup a frame from one cluster and restore it
to a different one -- even if the topology of the new cluster is
different.
