Long explanation, but hopefully answers any questions.
We don't like changing the default behavior of Swift unless there's a
really good reason and, up until now, I've tried doing this with this
new db_preallocation setting.
For clusters with dedicated account/container servers that usually
have fewer disks overall but SSD for speed, having db_preallocation
on will gobble up disk space quite quickly and the fragmentation it's
designed to fight isn't that big a speed impact to SSDs anyway.
For clusters with account/container servers spread across all servers
along with object servers usually having standard disks for cost,
having db_preallocation off will cause very fragmented database files
impacting speed, sometimes dramatically.
Weighing these two negatives, it seems the second is the lesser evil.
The first can cause disks to fill up and disable the cluster. The
second will cause performance degradation, but the cluster will still
function.
Furthermore, if just one piece of code that touches all databases
runs with db_preallocation on, it's effectively on for the whole
cluster. We discovered this most recently when we finally configured
everything within the Swift codebase to have db_preallocation off,
only to find out Slogging didn't know about the new setting and so
ran with it on and starting filling up SSDs.
So that's why I'm proposing this change to the default behavior.
We will definitely need to post a prominent notice of this change
with the next release.
Change-Id: I48a43439264cff5d03c14ec8787f718ee44e78ea
While fixing something else, the strange code in the test suite
presented itself. Looks like a massive copy-paste error and a couple
of random oddities.
Change-Id: I191e8cd9299b9336b0600363780d2930a04d1fd5
Documentation, including a list of metrics reported and their semantics,
is in the Admin Guide in a new section, "Reporting Metrics to StatsD".
An optional "metric prefix" may be configured which will be prepended to
every metric name sent to StatsD.
Here is the rationale for doing a deep integration like this versus only
sending metrics to StatsD in middleware. It's the only way to report
some internal activities of Swift in a real-time manner. So to have one
way of reporting to StatsD and one place/style of configuration, even
some things (like, say, timing of PUT requests into the proxy-server)
which could be logged via middleware are consistently logged the same
way (deep integration via the logger delegate methods).
When log_statsd_host is configured, get_logger() injects a
swift.common.utils.StatsdClient object into the logger as
logger.statsd_client. Then a set of delegate methods on LogAdapter
either pass through to the StatsdClient object or become no-ops. This
allows StatsD logging to look like:
self.logger.increment('some.metric.here')
and do the right thing in all cases and with no messy conditional logic.
I wanted to use the pystatsd module for the StatsD client, but the
version on PyPi is lagging the git repo (and is missing both the prefix
functionality and timing_since() method). So I wrote my
swift.common.utils.StatsdClient. The interface is the same as
pystatsd.Client, but the code was written from scratch. It's pretty
simple, and the tests I added cover it. This also frees Swift from an
optional dependency on the pystatsd module, making this feature easier
to enable.
There's test coverage for the new code and all existing tests continue
to pass.
Refactored out _one_audit_pass() method in swift/account/auditor.py and
swift/container/auditor.py.
Fixed some misc. PEP8 violations.
Misc test cleanups and refactorings (particularly the way "fake logging"
is handled).
Change-Id: Ie968a9ae8771f59ee7591e2ae11999c44bfe33b2
Also add new exception class SwiftConfigurationError,
that can't be used to indicate that swift parameters
in swift conf files are not correct.
Change-Id: I39bff9068a19c8e1c1b4aac38cb756c5e46d75e6
It was loading the ring off disk once to print the primary nodes, and
then loading the whole thing off disk again to print the handoff
nodes. Changed it to only load the ring off disk once.
Change-Id: I6f4cd0af9762e1e69660c3eb20586590b5339e5f
This commit introduces a new algorithm for assigning partition
replicas to devices. Basically, the ring builder organizes the devices
into tiers (first zone, then IP/port, then device ID). When placing a
replica, the ring builder looks for the emptiest device (biggest
parts_wanted) in the furthest-away tier.
In the case where zone-count >= replica-count, the new algorithm will
give the same results as the one it replaces. Thus, no migration is
needed.
In the case where zone-count < replica-count, the new algorithm
behaves differently from the old algorithm. The new algorithm will
distribute things evenly at each tier so that the replication is as
high-quality as possible, given the circumstances. The old algorithm
would just crash, so again, no migration is needed.
Handoffs have also been updated to use the new algorithm. When
generating handoff nodes, first the ring looks for nodes in other
zones, then other ips/ports, then any other drive. The first handoff
nodes (the ones in other zones) will be the same as before; this
commit just extends the list of handoff nodes.
The proxy server and replicators have been altered to avoid looking at
the ring's replica count directly. Previously, with a replica count of
C, RingData.get_nodes() and RingData.get_part_nodes() would return
lists of length C, so some other code used the replica count when it
needed the number of nodes. If two of a partition's replicas are on
the same device (e.g. with 3 replicas, 2 devices), then that
assumption is no longer true. Fortunately, all the proxy server and
replicators really needed was the number of nodes returned, which they
already had. (Bonus: now the only code that mentions replica_count
directly is in the ring and the ring builder.)
Change-Id: Iba2929edfc6ece89791890d0635d4763d821a3aa
The code has moved to https://github.com/notmyname/swift-cnamelookup.
For current users of cname lookup, this will require installing the new
package and changing the "use" line of the cname lookup conf section's
to:
[filter:cname_lookup]
use = egg:swift_cnamelookup#swift_cnamelookup
And then 'swift-init proxy reload'.
Change-Id: If622486ddb04a53251244c9840aa3cfe72168fc5
Rate Limit middleware is now at
http://dpgoetz.github.com/swift-ratelimit/
For current users of Rate Limit, this will require installing the new
package and changing the "use" line of the ratelimit conf section to:
[filter:ratelimit]
use = egg:swiftratelimit#middleware
And then 'swift-init proxy reload'.
Change-Id: I2ab774e9cee9fba4103c1be4bea6d52d1adb29f7
The code has moved to https://github.com/notmyname/swift-domainremap.
For current users of domain remap, this will require installing the new
package and changing the "use" line of the domain remap conf section's
to:
[filter:domain_remap]
use = egg:swift_domainremap#swift_domainremap
And then 'swift-init proxy reload'.
Change-Id: I710caf9b991f9d37df36b826ae4338086d0ec36d
TempURL/FormPOST is now at http://gholt.github.com/swift-tempurl/
For current users of TempURL/FormPOST, this will require installing the new
package and changing the "use" line of the tempurl and formpost conf section's
to:
[filter:tempurl]
use = egg:swifttempurl#tempurl
[filter:formpost]
use = egg:swifttempurl#formpost
And then 'swift-init proxy reload'.
Change-Id: I5bddf7f9e09ee07815530a41c46ff901fc21b447
StaticWeb is now at http://gholt.github.com/swift-staticweb/
For current users of StaticWeb, this will require installing the new
package and changing the "use" line of the staticweb filter conf
section to:
use = egg:swiftstaticweb#middleware
And then 'swift-init proxy reload'.
Change-Id: Iab32adb5927698a667c5c6d6a572c44ca23414eb
In the interest of keeping the core Swift code repository less
complex, but still offering a quick way to find associated projects
that enhance or use Swift, I've added this new Associated Projects
page prominently to the Swift documentation.
This will allow much less barrier to entry on enhancing Swift as
other projects can work independently and will only need to wait on
the core Swift project for approval of minimal tweaks to the core
Swift code base.
It will also allow an easy central place to find cool associated
projects that otherwise might go unnoticed or even duplicated.
The plan is to move non-essential projects that are currently
embedded in the Swift repository out into their own projects with
links to them on this new page. This would include items such as
(just what I can think of right now): bin/swift command line tool and
clients, swift-bench, swift-dispersion, TempURL, FormPost, StaticWeb,
Rate Limiting, Swift3, Domain Remap, and CNAME Lookup.
After all that is done, those projects will be able to move forward
much more quickly and new developers for Swift itself will have much
less to learn and get confused about.
Change-Id: Ib8447d8bd480f0a3d8f0413137ccdba73a11dd91
`swift-ring-builder X.builder [add|set_weight|set_info|remove]` can
now work on multiple devices at once.
This allows for faster bulk operations; for example, if an
administrator has to add 48 new devices to the ring, then this lets
them do it in one command invocation. Since each invocation of
swift-ring-builder follows a deserialize-operate-serialize pattern,
using the bulk form of the commands on N devices will save N-1
[de]serializations.
Change-Id: Ibf77528f28026866af3c94d0370181c8013d5bc5
bug 701248
bug 819303
This change makes syslog optional, by providing a unit test
config with the ability to cause test/unit/__init__.py to
replace SysLogHandler with a fake logging class. The
default behavior is unchanged.
FakeLogger now inherits directly from Handler and mocks out
its API - this was a backward-compatibility issue.
Change-Id: I653dec148c4f6cf81759de03964c6a3290c1a290
The listing of containers was inclusive whereas the listing of
objects was exclusive. I searched and searched and only found
end_marker usage with listings of objects so I changed the listings
of containers to match that.
Change-Id: Ia8eb66a7ceaef28c698e2d4e19dd5dfd9197a911
On a relatively recent build of swift, all my scripts blew up with
"No tenant specified". It was caused by the fix to add --os_tenant_name,
commit ID: 208b8e85a80e46ddb49dc2035cb292570a20c7db
This patch restores the old behavior. I tested it to work with old
swauth-based Swift, new Keystone-based Swift, in the latter case using
both -U and --os_tenant_name arguments.
Note that this patch permits to use a literal colon in the user name
with the new syntax, as long as tenant is specified. Empty tenant
names are not allowed with either syntax.
Change-Id: I7785e6981a9d6281d0421c43875ee19d61d5ff43
Bug: 982909
