Instead of using a separate .durable file to indicate
the durable status of a .data file, rename the .data
to include a durable marker in the filename. This saves
one inode for every EC fragment archive.
An EC policy PUT will, as before, first rename a temp
file to:
<timestamp>#<frag_index>.data
but now, when the object is committed, that file will be
renamed:
<timestamp>#<frag_index>#d.data
with the '#d' suffix marking the data file as durable.
Diskfile suffix hashing returns the same result when the
new durable-data filename or the legacy durable file is
found in an object directory. A fragment archive that has
been created on an upgraded object server will therefore
appear to be in the same state, as far as the consistency
engine is concerned, as the same fragment archive created
on an older object server.
Since legacy .durable files will still exist in deployed
clusters, many of the unit tests scenarios have been
duplicated for both new durable-data filenames and legacy
durable files.
Change-Id: I6f1f62d47be0b0ac7919888c77480a636f11f607
This patch improves EC GET response handling:
- The proxy no longer requires all object servers to have a
durable file for the fragment archive that they return in
response to a GET. The proxy will now be satisfied if just
one object server has a durable file at the same timestamp
as fragments from other object servers.
This means that the proxy can now successfully GET an
object that had missing durable files when it was PUT.
- The proxy will now ensure that it has a quorum of *unique*
fragment indexes from object servers before considering a
GET to be successful.
- The proxy is now able to fetch multiple fragment archives
having different indexes from the same node. This enables
the proxy to successfully GET an object that has some
fragments that have landed on the same node, for example
after a rebalance.
This new behavior is facilitated by an exchange of new
headers on a GET request and response between the proxy and
object servers.
An object server now includes with a GET (or HEAD) response:
- X-Backend-Fragments: the value of this describes all
fragment archive indexes that the server has for the
object by encoding a map of the form: timestamp -> <list
of fragment indexes>
- X-Backend-Durable-Timestamp: the value of this is the
internal form of the timestamp of the newest durable file
that was found, if any.
- X-Backend-Data-Timestamp: the value of this is the
internal form of the timestamp of the data file that was
used to construct the diskfile.
A proxy server now includes with a GET request:
- X-Backend-Fragment-Preferences: the value of this
describes the proxy's current preference with respect to
those fragments that it would have object servers
return. It encodes a list of timestamp, and for each
timestamp a list of fragment indexes that the proxy does
NOT require (because it already has them).
The presence of a X-Backend-Fragment-Preferences header
(even one with an empty list as its value) will cause the
object server to search for the most appropriate fragment
to return, disregarding the existence or not of any
durable file. The object server assumes that the proxy
knows best.
Closes-Bug: 1469094
Closes-Bug: 1484598
Change-Id: I2310981fd1c4622ff5d1a739cbcc59637ffe3fc3
Co-Authored-By: Paul Luse <paul.e.luse@intel.com>
Co-Authored-By: Clay Gerrard <clay.gerrard@gmail.com>
This removes notes stating support for Erasure coding as beta. Questions
regarding the stability of EC are coming up regularly, and are often referring
to the docs that state EC as still in beta.
Besides this, a note marking statsd support as beta has been removed as well.
Change-Id: If4fb6a5c4cb741d42953db3cee8cb17a1d774e15
Some doc files and swift.conf-sample were added execute permissions in past changes.
This patch remove execute permissions from them.
Change-Id: Id8844989a8321578e9207566ebd6660f5b9523f0
liberasurecode_rs_vand is build-in liberasurecode, so you don't need
another depedency libjerasure2.
liberasurecode_rs_vand is supported by pyeclib from 1.0.8
version, so bumping version up.
Closes-Bug: #1534325
Change-Id: If2d96875694df8fd48c5278395859aaa165cb566
The major functionality of EC has been released for Liberty and
the beta version of the code has been removed since it is now
in production.
Change-Id: If60712045fb1af803093d6753fcd60434e637772
Update the doc to reflect the change [1] to ndata + 1
.durable files being committed before a success response
is returned for a PUT.
[1] Ifd36790faa0a5d00ec79c23d1f96a332a0ca0f0b
Change-Id: I1744d457bda8a52eb2451029c4031962e92c2bb7
Update the EC overview docs 'under the hood' section to reflect the
change in durable file parity from 2 to ec_nparity + 1 [1].
Also fix some typos and cleanup the text.
[1] change id I80d666f61273e589d0990baa78fd657b3470785d
Change-Id: I23f6299da59ba8357da2bb5976d879d9a4bb173e
This doc is being updated to specify the replicas count parameter
to build an EC ring that enforces both data and parity placements
for each partition.
Change-Id: I770ad268e4017e610be3357e89b89f0b7d3c18af
Closes-Bug: 1487203
