Commit Graph

591 Commits (c3cc25f55243bbe4e6b84c4e1617dd473695251b)

Author SHA1 Message Date
Julius Volz c3d6abc8e6 Fix some lint errors (#3334)
I left the promql ones and some others untouched as I remember that @fabxc
prefers them that way.
2017-10-23 14:57:30 +01:00
Julius Volz 2846d62573 Fix staticcheck issue in test (#3331)
staticcheck fails with:
storage/remote/read_test.go:199:27: do not pass a nil Context, even if a function permits it; pass context.TODO if you are unsure about which Context to use (SA1012)
2017-10-23 11:51:48 +01:00
Brian Brazil 4a50f547c8 removeLabels needs a pointer to work. (#3326) 2017-10-21 08:29:03 +01:00
Thibault Chataigner bf4a279a91 Remote storage reads based on oldest timestamp in primary storage (#3129)
Currently all read queries are simply pushed to remote read clients.
This is fine, except for remote storage for wich it unefficient and
make query slower even if remote read is unnecessary.
So we need instead to compare the oldest timestamp in primary/local
storage with the query range lower boundary. If the oldest timestamp
is older than the mint parameter, then there is no need for remote read.
This is an optionnal behavior per remote read client.

Signed-off-by: Thibault Chataigner <t.chataigner@criteo.com>
2017-10-18 12:08:14 +01:00
Julius Volz 9ef8518b37 Remove "package remote" garbage from license headers (#3304) 2017-10-17 02:26:38 +01:00
Brian Brazil 73dc96e7f5 Fix leak of ticker in remote storage queue manager. 2017-10-09 19:44:03 +01:00
Brian Brazil ee88f0d222 Ensure all values are used or _ 2017-10-09 19:44:03 +01:00
Brian Brazil 37ec2d5283 Fix off by one error in concreteSeriesSet (#3262) 2017-10-09 13:37:58 +01:00
Marc Sluiter 6a633eece1 Added go-conntrack for monitoring http connections (#3241)
Added metrics for in- and outgoing traffic with go-conntrack.
2017-10-06 11:22:19 +01:00
Julius Volz f7e8348a88 Re-add contexts to storage.Storage.Querier() (#3230)
* Re-add contexts to storage.Storage.Querier()

These are needed when replacing the storage by a multi-tenant
implementation where the tenant is stored in the context.

The 1.x query interfaces already had contexts, but they got lost in 2.x.

* Convert promql.Engine to use native contexts
2017-10-04 21:04:15 +02:00
Fabian Reinartz d21f149745 *: migrate to go-kit/log 2017-09-08 22:01:51 +05:30
Fabian Reinartz 0efecea6d4 Adapt storage APIs to uint64 references 2017-09-07 14:14:41 +02:00
Tom Wilkie b11bc8ae24 Fix some comments. 2017-08-01 11:19:35 +01:00
Tom Wilkie ec999ff397 Prevent number of remote write shards from going negative.
This can happen in the situation where the system scales up the number of shards massively (to deal with some backlog), then scales it down again as the number of samples sent during the time period is less than the number received.
2017-07-19 16:32:09 +01:00
Tom Wilkie a09acdcc5b Make concreteSeriersIterator behave. 2017-07-13 18:33:08 +01:00
Tom Wilkie b568ace7ce Move protos to ./prompb 2017-07-12 22:06:35 +01:00
Tom Wilkie db8128ceeb Add label set as first parameter to AddFast, ingored by TSDB adapter. 2017-07-12 15:20:12 +01:00
Tom Wilkie 2dda5775e3 Initial port of remote storage to v2. 2017-07-12 12:27:57 +01:00
Fabian Reinartz 8ffc851147 Merge branch 'master' into dev-2.0 2017-04-04 15:17:56 +02:00
Julius Volz 5a896033e3 Add remote read external label handling (#2555)
* Add remote read external label handling

This implements rule 1 and 2 from
https://docs.google.com/document/d/188YauRgfF0J4CYMigLsVNN34V_kUwKnApBs2dQMfBbs/edit

* Use more descriptive example labels in read test

* Add comment for querier.addExternalLabels()

* Make argument naming in removeLabels() more generic
2017-04-02 17:48:15 +02:00
Julius Volz 3f23aa2cc7 Add headers to indicate remote read/write version
Also add Content-Type header.
2017-03-24 17:39:51 +01:00
Julius Volz 94acd3f1d8 Add fanin tests and fix uncovered bugs 2017-03-21 00:08:17 +01:00
Julius Volz 9b33cfc457 Fix/unify context-based remote storage timeouts 2017-03-20 14:17:06 +01:00
Julius Volz 815762a4ad Move retrieval.NewHTTPClient -> httputil.NewClientFromConfig 2017-03-20 14:17:04 +01:00
Julius Volz eb14678a25 Make remote read/write use config.HTTPClientConfig 2017-03-20 13:37:50 +01:00
Julius Volz 406b65d0dc Rename remote.Storage to remote.Writer 2017-03-20 13:15:28 +01:00
Julius Volz 02395a224d [WIP] Remote Read 2017-03-20 13:13:44 +01:00
Tom Wilkie 75bb0f3253 Review feedback 2017-03-13 21:24:49 +00:00
Tom Wilkie 77cce900b8 Fix tests 2017-03-13 15:21:59 +00:00
Tom Wilkie b48799a01e Add license stanza 2017-03-13 14:50:15 +00:00
Tom Wilkie 9d22f030cf Dynamically reshard the QueueManager based on observed load. 2017-03-13 14:41:16 +00:00
Tom Wilkie 1ab893c6ec Limit 'discarding sample' logs to 1 every 10s (#2446)
* Limit 'discarding sample' logs to 1 every 10s

* Include the vendored library

* Review feedback
2017-02-23 19:20:39 +01:00
Julius Volz 2f39dbc8b3 Rename StorageQueueManager -> QueueManager 2017-02-21 21:45:43 +01:00
Julius Volz e9476b35d5 Re-add multiple remote writers
Each remote write endpoint gets its own set of relabeling rules.

This is based on the (yet-to-be-merged)
https://github.com/prometheus/prometheus/pull/2419, which removes legacy
remote write implementations.
2017-02-20 13:23:12 +01:00
Julius Volz beb3c4b389 Remove legacy remote storage implementations
This removes legacy support for specific remote storage systems in favor
of only offering the generic remote write protocol. An example bridge
application that translates from the generic protocol to each of those
legacy backends is still provided at:

documentation/examples/remote_storage/remote_storage_bridge

See also https://github.com/prometheus/prometheus/issues/10

The next step in the plan is to re-add support for multiple remote
storages.
2017-02-14 17:52:05 +01:00
Brian Brazil 1b8a474612 Don't clone the metric if there's no remote writes.
The metric clone can't be further optimised, and is a
non-trivial memory allocation cost so fast path it
if there's no remote writes configured.
2016-12-21 11:34:48 +00:00
Julius Volz c7932aa009 Remove gRPC leftovers in protobuf definitions 2016-10-05 17:31:04 +02:00
Brian Brazil 77605649a9 Add support for remote write relabelling.
Switch back to a single remote writer, as we were only ever meant to
have one and the relabel semantics are clearer that way.
2016-10-05 07:43:19 +01:00
Matthew Campbell 67d76e3a5d timeseries: store varbit encoded data into cassandra 2016-09-21 17:56:55 +02:00
Tom Wilkie 4520e12440 Add HTTP Basic Auth & TLS support to the generic write path. (#1957)
* Add config, HTTP Basic Auth and TLS support to the generic write path.

- Move generic write path configuration to the config file
- Factor out config.TLSConfig -> tlf.Config translation
- Support TLSConfig for generic remote storage
- Rename Run to Start, and make it non-blocking.
- Dedupe code in httputil for TLS config.
- Make remote queue metrics global.
2016-09-19 22:47:51 +02:00
Tom Wilkie d83879210c Switch back to protos over HTTP, instead of GRPC.
My aim is to support the new grpc generic write path in Frankenstein.  On the surface this seems easy - however I've hit a number of problems that make me think it might be better to not use grpc just yet.

The explanation of the problems requires a little background.  At weave, traffic to frankenstein need to go through a couple of services first, for SSL and to be authenticated.  So traffic goes:

    internet -> frontend -> authfe -> frankenstein

- The frontend is Nginx, and adds/removes SSL.  Its done this way for legacy reasons, so the certs can be managed in one place, although eventually we imagine we'll merge it with authfe.  All traffic from frontend is sent to authfe.
- Authfe checks the auth tokens / cookie etc and then picks the service to forward the RPC to.
- Frankenstein accepts the reads and does the right thing with them.

First problem I hit was Nginx won't proxy http2 requests - it can accept them, but all calls downstream are http1 (see https://trac.nginx.org/nginx/ticket/923).  This wasn't such a big deal, so it now looks like:

    internet --(grpc/http2)--> frontend --(grpc/http1)--> authfe --(grpc/http1)--> frankenstein

Next problem was golang grpc server won't accept http1 requests (see https://groups.google.com/forum/#!topic/grpc-io/JnjCYGPMUms).  It is possible to link a grpc server in with a normal go http mux, as long as the mux server is serving over SSL, as the golang http client & server won't do http2 over anything other than an SSL connection.  This would require making all our service to service comms SSL.  So I had a go a writing a grpc http1 server, and got pretty far.  But is was a bit of a mess.

So finally I thought I'd make a separate grpc frontend for this, running in parallel with the frontend/authfe combo on a different port - and first up I'd need a grpc reverse proxy.  Ideally we'd have some nice, generic reverse proxy that only knew about a map from service names -> downstream service, and didn't need to decode & re-encode every request as it went through.  It seems like this can't be done with golang's grpc library - see https://github.com/mwitkow/grpc-proxy/issues/1.

And then I was surprised to find you can't do grpc from browsers! See http://www.grpc.io/faq/ - not important to us, but I'm starting to question why we decided to use grpc in the first place?

It would seem we could have most of the benefits of grpc with protos over HTTP, and this wouldn't preclude moving to grpc when its a bit more mature?  In fact, the grcp FAQ even admits as much:

> Why is gRPC better than any binary blob over HTTP/2?
> This is largely what gRPC is on the wire.
2016-09-15 23:21:54 +01:00
Tobias Schmidt 29ced0090f Fix common english misspellings 2016-09-14 23:23:28 -04:00
Tobias Schmidt 8f3b62bfe4 Simplify struct initialization 2016-09-14 23:13:27 -04:00
Fabian Reinartz 7bd7e63f97 storage: fix struct alignment issue in test
The uint64 `numCalls` ends up being not word-aligned on certain architectures,
which makes atomic reads/writes panic.
2016-09-11 00:32:57 +02:00
Tom Wilkie d41d91388f Update for new generic remote storage. 2016-08-30 17:43:29 +02:00
Tom Wilkie a6931b71e8 Rationalise retrieval metrics so we have the state (success/failed) on both samples and batches, in a consistent fashion.
Also, report total queue capacity of all queues, i.e. capacity * shards.
2016-08-30 17:42:42 +02:00
Tom Wilkie ece12bff93 Shard/parrallelise samples by fingerprint in StorageQueueManager
By splitting the single queue into multiple queues and flushing each individual queue in serially (and all queues in parallel), we can guarantee to preserve the order of timestampsin samples sent to downstream systems.
2016-08-30 17:42:36 +02:00
Julius Volz aa3f2b7216 Generic write cleanups and changes.
- fold metric name into labels
- return initialization errors back to main
- add snappy compression
- better context handling
- pre-allocation of labels
- remove generic naming
- other cleanups
2016-08-30 17:24:48 +02:00
Brian Brazil 36d2c4bd0b Add generic write path using grpc.
This uses a new proto format, with scope for multiple samples per
timeseries in future. This will allow users to pump samples out to
whatever they like without having to change the core Prometheus code.

There's also an example receiver to save users figuring out the
boilerplate themselves.
2016-08-30 17:19:18 +02:00
Dan Milstein 764ceaa939 Add timeout to test, cap waiting at 1 second 2016-08-24 11:30:38 -04:00
Dan Milstein 007907b410 Fix one of the tests for a remote storage QueueManager
Specifically, the TestSpawnNotMoreThanMaxConcurrentSendsGoroutines was failing on a fresh checkout of master.

The test had a race condition -- it would only pass if one of the
spawned goroutines happened to very quickly pull a set of samples off an
internal queue.

This patch rewrites the test so that it deterministically waits until
all samples have been pulled off that queue.  In case of errors, it also
now reports on the difference between what it expected and what it found.

I verified that, if the code under test is deliberately broken, the test
successfully reports on that.
2016-08-23 16:26:33 -04:00
Dmitry Vorobev 273e457da4 web: return status code and error message for config resource 2016-07-15 10:15:24 +02:00
beorn7 064b57858e Consistently use the `Seconds()` method for conversion of durations
This also fixes one remaining case of recording integral numbers
of seconds only for a metric, i.e. this will probably fix #1796.
2016-07-07 15:24:35 +02:00
Dmitry Vorobev bd2a770015 storage/remote: Spawn not more than "maxConcurrentSends" goroutines. 2016-05-19 16:15:04 +02:00
Dmitry Savintsev 7fdb62c253 fix several minor golint style issues 2016-05-11 14:26:18 +02:00
Jonathan Boulle 38098f8c95 Add missing license headers
Prometheus is Apache 2 licensed, and most source files have the
appropriate copyright license header, but some were missing it without
apparent reason. Correct that by adding it.
2016-04-13 16:08:22 +02:00
Tobias Schmidt e82ef154ee Remove unused code leftovers 2016-04-02 20:20:55 -04:00
Julius Volz d3b53bd7f0 Fix comment about Graphite mapping of dimensions. 2016-03-23 00:38:32 +01:00
Fabian Reinartz 59f1e722df Return error on sample appending 2016-02-02 14:01:44 +01:00
beorn7 ec08c9a391 Rework the way to communicate backpressure (AKA suspended ingestion)
This gives up on the idea to communicate throuh the Append() call (by
either not returning as it is now or returning an error as
suggested/explored elsewhere). Here I have added a Throttled() call,
which has the advantage that it can be called before a whole _batch_
of Append()'s. Scrapes will happen completely or not at all. Same for
rule group evaluations. That's a highly desired behavior (as discussed
elsewhere). The code is even simpler now as the whole ingestion buffer
could be removed.

Logging of throttled mode has been streamlined and will create at most
one message per minute.
2016-02-01 14:45:44 +01:00
Corentin Chary 7b6c3e556c Use '.' instead of '=' to separate labels from their values in Graphite
Using .label=value. was weird to use in Graphite and didn't bring much value.
2016-01-11 13:57:14 +01:00
Corentin Chary a2e4439086 Add support for remote storage on Graphite
Allows to use graphite over tcp or udp. Metrics labels
and values are used to construct a valid Graphite path
in a way that will allow us to eventually read them back
and reconstruct the metrics.

For example, this metric:

model.Metric{
	model.MetricNameLabel: "test:metric",
	"testlabel":           "test:value",
	"testlabel2":           "test:value",
)

Will become:

test:metric.testlabel=test:value.testlabel2=test:value

escape.go takes care of escaping values to match Graphite
character set, it basically uses percent-encoding as a fallback
wich will work pretty will in the graphite/grafana world.

The remote storage module also has an optional 'prefix' parameter
to prefix all metrics with a path (for example, 'prometheus.').

Graphite URLs are simply in the form tcp://host:port or
udp://host:port.
2015-11-10 07:58:57 +01:00
Fabian Reinartz e3b6ec9784 Switch to common/log 2015-10-03 10:21:43 +02:00
Julius Volz dac26cef71 Rename global "labels" config option to "external_labels". 2015-09-29 20:54:20 +02:00
Julius Volz eeb1da36ac Fix InfluxDB write support to work with InfluxDB 0.9.x.
Because the InfluxDB client library currently pulls in multiple MBs of
unnecessary dependencies, I have modified and cut up the vendored
version to only pull in the few pieces that are actually needed.

On InfluxDB's side, this dependency issue is tracked in:

https://github.com/influxdb/influxdb/issues/3447

Hopefully, it will be resolved soon.

If a password is needed for InfluxDB, it may be supplied via the
INFLUXDB_PW environment variable.
2015-09-16 17:40:03 +02:00
Julius Volz 5f77fce578 Improve remote storage queue manager metrics. 2015-09-16 17:20:23 +02:00
Fabian Reinartz 8fa719f778 Attach global labels to remote storage samples 2015-09-03 16:38:04 +02:00
Julius Volz 963ad82dcb Fix "go vet" errors.
I ignored all errors of the type "composite literal uses unkeyed
fields". Most of them are wrong because of
https://github.com/golang/go/issues/9171.
2015-08-26 02:05:04 +02:00
Fabian Reinartz 438e232c9b Fix grouping of import blocks 2015-08-22 09:42:45 +02:00
Fabian Reinartz 306e8468a0 Switch from client_golang/model to common/model 2015-08-21 13:33:38 +02:00
Will Rouesnel 7810448dbe Add proxy_url parameter to allow specifying per-job HTTP proxy servers
Allow scrape_configs to have an optional proxy_url option which specifies
a proxy to be used for all connections to hosts in that config.

Internally this modifies the various client functions to take a *url.URL pointer
which currently must point to an HTTP proxy (but has been left open-ended to
allow the url format to be extended to support others, such as maybe SOCKS if
needed).
2015-08-08 04:29:27 +10:00
Fabian Reinartz 23e77450ff main: cleanup initialization of remote storage. 2015-06-23 18:24:48 +02:00
Fabian Reinartz b105e26f4d storage: remove global flags 2015-06-15 19:01:06 +02:00
Fabian Reinartz 0de6edbdfc Move pkg/ to util/ 2015-06-01 21:12:32 +02:00
Fabian Reinartz dfaf31a1da Move web/httputils to pkg/httputil and add DeadlineClient to it 2015-06-01 21:12:31 +02:00
Julius Volz 267fd34156 Switch Prometheus to use github.com/prometheus/log.
This change is conceptually very simple, although the diff is large. It
switches logging from "github.com/golang/glog" to
"github.com/prometheus/log", while not actually changing any log
messages. V(1)-style logging has been changed to be log.Debug*().
2015-05-20 18:19:32 +02:00
Julius Volz 593e565688 Allow writing to InfluxDB/OpenTSDB at the same time. 2015-04-02 20:24:38 +02:00
Julius Volz 61fb688dd9 Add experimental InfluxDB write support. 2015-04-01 02:03:16 +02:00
beorn7 be11cb2b07 Remove the sample ingestion channel.
The one central sample ingestion channel has caused a variety of
trouble. This commit removes it. Targets and rule evaluation call an
Append method directly now. To incorporate multiple storage backends
(like OpenTSDB), storage.Tee forks the Append into two different
appenders.

Note that the tsdb queue manager had its own queue anyway. It was a
queue after a queue... Much queue, so overhead...

Targets have their own little buffer (implemented as a channel) to
avoid stalling during an http scrape. But a new scrape will only be
started once the old one is fully ingested.

The contraption of three pipelined ingesters was removed. A Target is
an ingester itself now. Despite more logic in Target, things should be
less confusing now.

Also, remove lint and vet warnings in ast.go.
2015-03-15 14:08:22 +01:00
beorn7 8a1c195b54 Move emptiness check to the receivers. 2015-02-12 19:47:24 +01:00
Bjoern Rabenstein 5859b74f1b Clean up license issues.
- Move CONTRIBUTORS.md to the more common AUTHORS.
- Added the required NOTICE file.
- Changed "Prometheus Team" to "The Prometheus Authors".
- Reverted the erroneous changes to the Apache License.
2015-01-21 20:07:45 +01:00
Bjoern Rabenstein ae70eac97d Adjust the partitioning by outcome. 2015-01-13 18:34:56 +01:00
Bjoern Rabenstein 74c143c4c9 Improve scraper shutdown time.
- Stop target pools in parallel.
- Stop individual scrapers in goroutines, too.
- Timing tweaks.

Change-Id: I9dff1ee18616694f14b04408eaf1625d0f989696
2014-11-25 17:10:39 +01:00
Bjoern Rabenstein 443dd33805 Improve instrumentation in storage.
Also, fix some other minor bugs.

Change-Id: If72f1c058b0f47d3e378fdf80228d7e9a8db06c7
2014-11-25 17:09:04 +01:00
Bjoern Rabenstein b3ed9aa7a2 Clean up start-up and shut-down.
Change-Id: Idff4bbb0a15a9f879bfbb3da5b1025179cab5e2c
2014-11-25 17:08:45 +01:00
Bjoern Rabenstein 1909686789 Make metrics exported by the Prometheus server itself more consistent.
- Always spell out the time unit (e.g. milliseconds instead of ms).

- Remove "_total" from the names of metrics that are not counters.

- Make use of the "Namespace" and "Subsystem" fields in the options.

- Removed the "capacity" facet from all metrics about channels/queues.
  These are all fixed via command line flags and will never change
  during the runtime of a process. Also, they should not be part of
  the same metric family. I have added separate metrics for the
  capacity of queues as convenience. (They will never change and are
  only set once.)

- I left "metric_disk_latency_microseconds" unchanged, although that
  metric measures the latency of the storage device, even if it is not
  a spinning disk. "SSD" is read by many as "solid state disk", so
  it's not too far off. (It should be "solid state drive", of course,
  but "metric_drive_latency_microseconds" is probably confusing.)

- Brian suggested to not mix "failure" and "success" outcome in the
  same metric family (distinguished by labels). For now, I left it as
  it is. We are touching some bigger issue here, especially as other
  parts in the Prometheus ecosystem are following the same
  principle. We still need to come to terms here and then change
  things consistently everywhere.

Change-Id: If799458b450d18f78500f05990301c12525197d3
2014-11-25 17:02:00 +01:00
Bjoern Rabenstein 8956faeccb Migrate to new client_golang.
This change will only be submitted when the new client_golang has been
moved to the new version.

Change-Id: Ifceb59333072a08286a8ac910709a8ba2e3a1581
2014-11-25 17:01:59 +01:00
Bjoern Rabenstein 257b720e87 Fix typo.
Change-Id: I6e7edcb48ace7fe4d6de4ff16519da5bb326b6ce
2014-03-25 12:22:18 +01:00
Bjoern Rabenstein caf47b2fbc New encoding for OpenTSDB tag values (and metric names).
Change-Id: I0f4393f638c6e2bb2b2ce14e58e38b49ce456da8
2014-03-21 17:18:44 +01:00
Bjoern Rabenstein 6bc083f38b Major code cleanup in storage.
- Mostly docstring fixed/additions.
  (Please review these carefully, since most of them were missing, I
  had to guess them from an outsider's perspective. (Which on the
  other hand proves how desperately required many of these docstrings
  are.))

- Removed all uses of new(...) to meet our own style guide (draft).

- Fixed all other 'go vet' and 'golint' issues (except those that are
  not fixable (i.e. caused by bugs in or by design of 'go vet' and
  'golint')).

- Some trivial refactorings, like reorder functions, minor renames, ...

- Some slightly less trivial refactoring, mostly to reduce code
  duplication by embedding types instead of writing many explicit
  forwarders.

- Cleaned up the interface structure a bit. (Most significant probably
  the removal of the View-like methods from MetricPersistenc. Now they
  are only in View and not duplicated anymore.)

- Removed dead code. (Probably not all of it, but it's a first
  step...)

- Fixed a leftover in storage/metric/end_to_end_test.go (that made
  some parts of the code never execute (incidentally, those parts
  were broken (and I fixed them, too))).

Change-Id: Ibcac069940d118a88f783314f5b4595dce6641d5
2014-02-27 15:22:37 +01:00
Julius Volz 61d26e8445 Add optional sample replication to OpenTSDB.
Prometheus needs long-term storage. Since we don't have enough resources
to build our own timeseries storage from scratch ontop of Riak,
Cassandra or a similar distributed datastore at the moment, we're
planning on using OpenTSDB as long-term storage for Prometheus. It's
data model is roughly compatible with that of Prometheus, with some
caveats.

As a first step, this adds write-only replication from Prometheus to
OpenTSDB, with the following things worth noting:

1)
I tried to keep the integration lightweight, meaning that anything
related to OpenTSDB is isolated to its own package and only main knows
about it (essentially it tees all samples to both the existing storage
and TSDB). It's not touching the existing TieredStorage at all to avoid
more complexity in that area. This might change in the future,
especially if we decide to implement a read path for OpenTSDB through
Prometheus as well.

2)
Backpressure while sending to OpenTSDB is handled by simply dropping
samples on the floor when the in-memory queue of samples destined for
OpenTSDB runs full.  Prometheus also only attempts to send samples once,
rather than implementing a complex retry algorithm. Thus, replication to
OpenTSDB is best-effort for now.  If needed, this may be extended in the
future.

3)
Samples are sent in batches of limited size to OpenTSDB. The optimal
batch size, timeout parameters, etc. may need to be adjusted in the
future.

4)
OpenTSDB has different rules for legal characters in tag (label) values.
While Prometheus allows any characters in label values, OpenTSDB limits
them to a to z, A to Z, 0 to 9, -, _, . and /. Currently any illegal
characters in Prometheus label values are simply replaced by an
underscore. Especially when integrating OpenTSDB with the read path in
Prometheus, we'll need to reconsider this: either we'll need to
introduce the same limitations for Prometheus labels or escape/encode
illegal characters in OpenTSDB in such a way that they are fully
decodable again when reading through Prometheus, so that corresponding
timeseries in both systems match in their labelsets.

Change-Id: I8394c9c55dbac3946a0fa497f566d5e6e2d600b5
2014-01-02 18:21:38 +01:00