Commit graph

192 commits

Author SHA1 Message Date
Daisy T 7d01ead689 change time.duration to model.duration for standardization (#4479)
Signed-off-by: Daisy T <daisyts@gmx.com>
2018-08-24 16:55:21 +02:00
Julius Volz 8fbe1b5133
Handle a bunch of unchecked errors (#4461)
There are many more (mostly finalizers like Close/Stop/etc.), but most of
the others seemed like one couldn't do much about them anyway.

Signed-off-by: Julius Volz <julius.volz@gmail.com>
2018-08-17 17:24:35 +02:00
Henri DF ffb7836c14 Send "Accept-Encoding" header in read request (#4421)
We should be doing this since we only accept Snappy-encoded responses.

Signed-off-by: Henri DF <henridf@gmail.com>
2018-07-26 12:45:04 +01:00
Henri DF 3abb2cc349 Fix typo (#4423)
Signed-off-by: Henri DF <henridf@gmail.com>
2018-07-26 08:49:53 +01:00
Goutham Veeramachaneni c28cc5076c Saner defaults and metrics for remote-write (#4279)
* Rename queueCapacity to shardCapacity
* Saner defaults for remote write
* Reduce allocs on retries

Signed-off-by: Goutham Veeramachaneni <cs14btech11014@iith.ac.in>
2018-07-18 05:15:16 +01:00
Thomas Jackson 92c6f0c92e Add offset to selectParams (#4226)
* Add Start/End to SelectParams
* Make remote read use the new selectParams for start/end

This commit will continue sending the start/end time of the remote read
query as the overarching promql time and the specific range of data that
the query is intersted in receiving a response to is now part of the
ReadHints (upstream discussion in #4226).

* Remove unused vendored code

The genproto.sh script was updated, but the code wasn't regenerated.
This simply removes the vendored deps that are no longer part of the
codegen output.

Signed-off-by: Thomas Jackson <jacksontj.89@gmail.com>
2018-07-18 04:58:00 +01:00
Tom Wilkie 0b189b2da9 Review feedback.
Signed-off-by: Tom Wilkie <tom.wilkie@gmail.com>
2018-06-18 17:21:12 +01:00
Corentin Chary 530107f8ef federation: nil pointer deference when using remove read
```
level=error ts=2018-06-13T07:19:04.515149169Z caller=stdlib.go:89 component=web caller="http: panic serving [::1" msg="]:56202: runtime error: invalid memory address or nil pointer dereference"
level=error ts=2018-06-13T07:19:04.516199547Z caller=stdlib.go:89 component=web caller="http: panic serving [::1" msg="]:56204: runtime error: invalid memory address or nil pointer dereference"
level=error ts=2018-06-13T07:19:04.51717692Z caller=stdlib.go:89 component=web caller="http: panic serving [::1" msg="]:56206: runtime error: invalid memory address or nil pointer dereference"
level=error ts=2018-06-13T07:19:04.564952878Z caller=stdlib.go:89 component=web caller="http: panic serving [::1" msg="]:56208: runtime error: invalid memory address or nil pointer dereference"
level=error ts=2018-06-13T07:19:04.566575791Z caller=stdlib.go:89 component=web caller="http: panic serving [::1" msg="]:56210: runtime error: invalid memory address or nil pointer dereference"
level=error ts=2018-06-13T07:19:04.567106063Z caller=stdlib.go:89 component=web caller="http: panic serving [::1" msg="]:56212: runtime error: invalid memory address or nil pointer dereference"
```

When remove read is enabled, federation will call `q.Select(nil, mset...)`
which will break remote reads because it currently doesn't handle empty
SelectParams.

Signed-off-by: Corentin Chary <c.chary@criteo.com>
2018-06-18 17:21:12 +01:00
Andreas Auernhammer 37d1bcf495 limit size of POST requests against remote read endpoint (#4239)
This commit fixes a denial-of-service issue of the remote
read endpoint. It limits the size of the POST request body
to 32 MB such that clients cannot write arbitrary amounts
of data to the server memory.

Fixes #4238

Signed-off-by: Andreas Auernhammer <aead@mail.de>
2018-06-08 08:19:20 +01:00
Bryan Boreham 3277aeefaa Add queue name to logger for remote writes
More than one remote_write destination can be configured, in which
case it's essential to know which one each log message refers to.

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>
2018-06-01 13:04:00 +00:00
Tom Wilkie b58199bf12 Review feedback.
Signed-off-by: Tom Wilkie <tom.wilkie@gmail.com>
2018-05-29 11:35:43 +01:00
Tom Wilkie 3353bbd018 Add proper unclean shutdown handling with a cancellable context.
Signed-off-by: Tom Wilkie <tom.wilkie@gmail.com>
2018-05-29 09:51:29 +01:00
Tom Wilkie e51d6c4b6c Make remote flush deadline a command line param.
Signed-off-by: Tom Wilkie <tom.wilkie@gmail.com>
2018-05-23 15:06:01 +01:00
Tom Wilkie a6c353613a Make the flush deadline configurable.
Signed-off-by: Tom Wilkie <tom.wilkie@gmail.com>
2018-05-23 15:04:36 +01:00
Tom Wilkie aa17263edd Remove WaitGroup and extra goroutine.
Signed-off-by: Tom Wilkie <tom.wilkie@gmail.com>
2018-05-23 15:04:34 +01:00
Tom Wilkie f3c61f8bb2 Only give remote queues 1 minute to flush samples on shutdown.
Signed-off-by: Tom Wilkie <tom.wilkie@gmail.com>
2018-05-23 15:04:32 +01:00
Henri DF 2952387ed1 Pass query hints down into remote read query proto (#4122)
Signed-off-by: Henri DF <henridf@gmail.com>
2018-05-08 09:48:13 +01:00
Adam Shannon 809881d7f5 support reading basic_auth password_file for HTTP basic auth (#4077)
Issue: https://github.com/prometheus/prometheus/issues/4076

Signed-off-by: Adam Shannon <adamkshannon@gmail.com>
2018-04-25 18:19:06 +01:00
Mario Trangoni 464e747f1e fix some comments typos (#4059) 2018-04-08 10:51:54 +01:00
Tom Wilkie dc860e7d0e Fix nit. 2018-03-12 16:48:51 +00:00
Tom Wilkie 390b018c90 Test sample timeout delivery. 2018-03-12 15:35:43 +00:00
Tom Wilkie 22d820ef8e Review feedback. 2018-03-12 14:27:48 +00:00
Tom Wilkie f8c9d375b6 Correctly stop the timer used in the remote write path. 2018-03-09 12:00:26 +00:00
ferhat elmas ffa673f7d8 General simplifications (#3887)
Another try as in #1516
2018-02-26 07:58:10 +00:00
Fabian Reinartz 7ccd4b39b8 *: implement query params
This adds a parameter to the storage selection interface which allows
query engine(s) to pass information about the operations surrounding a
data selection.
This can for example be used by remote storage backends to infer the
correct downsampling aggregates that need to be provided.
2018-02-13 12:17:22 +01:00
Tom Wilkie a730083cbf
Merge pull request #3731 from bboreham/reuse-timer
Re-use timer in remote storage queue
2018-02-05 10:54:08 +01:00
Krasi Georgiev b75428ec19 rename package retrieve to scrape
no fucnctinal changes just renaming retrieval to scrape
2018-02-01 09:55:07 +00:00
Bryan Boreham 8a4535e6ad Re-use timer instead of creating new ones on every sample
The docs for `time.After()` note that "The underlying Timer is not
recovered by the garbage collector until the timer fires".
2018-01-24 12:36:29 +00:00
Tom Wilkie f2c5399e39
Merge pull request #3561 from twiedenbein/master
fixed bug with initialization of queueconfig
2018-01-17 12:24:58 +00:00
Shubheksha Jalan 0471e64ad1 Use shared types from the common repo (#3674)
* refactor: use shared types from common repo, remove util/config

* vendor: add common/config

* fix nit
2018-01-11 16:10:25 +01:00
Shubheksha Jalan ec94df49d4 Refactor SD configuration to remove config dependency (#3629)
* refactor: move targetGroup struct and CheckOverflow() to their own package

* refactor: move auth and security related structs to a utility package, fix import error in utility package

* refactor: Azure SD, remove SD struct from config

* refactor: DNS SD, remove SD struct from config into dns package

* refactor: ec2 SD, move SD struct from config into the ec2 package

* refactor: file SD, move SD struct from config to file discovery package

* refactor: gce, move SD struct from config to gce discovery package

* refactor: move HTTPClientConfig and URL into util/config, fix import error in httputil

* refactor: consul, move SD struct from config into consul discovery package

* refactor: marathon, move SD struct from config into marathon discovery package

* refactor: triton, move SD struct from config to triton discovery package, fix test

* refactor: zookeeper, move SD structs from config to zookeeper discovery package

* refactor: openstack, remove SD struct from config, move into openstack discovery package

* refactor: kubernetes, move SD struct from config into kubernetes discovery package

* refactor: notifier, use targetgroup package instead of config

* refactor: tests for file, marathon, triton SD - use targetgroup package instead of config.TargetGroup

* refactor: retrieval, use targetgroup package instead of config.TargetGroup

* refactor: storage, use config util package

* refactor: discovery manager, use targetgroup package instead of config.TargetGroup

* refactor: use HTTPClient and TLS config from configUtil instead of config

* refactor: tests, use targetgroup package instead of config.TargetGroup

* refactor: fix tagetgroup.Group pointers that were removed by mistake

* refactor: openstack, kubernetes: drop prefixes

* refactor: remove import aliases forced due to vscode bug

* refactor: move main SD struct out of config into discovery/config

* refactor: rename configUtil to config_util

* refactor: rename yamlUtil to yaml_config

* refactor: kubernetes, remove prefixes

* refactor: move the TargetGroup package to discovery/

* refactor: fix order of imports
2017-12-29 21:01:34 +01:00
Tom Wiedenbein 937ac8c060
fixed bug with initialization of queueconfig
QueueConfigs would only ever initialize to the default settings, and would not pick up their respective values from YAML.
2017-12-08 02:11:45 -08:00
Fabian Reinartz 83cd270ea4 *: adapt to storage interface changes 2017-11-23 19:05:04 +01:00
Tobias Schmidt 7098c56474 Add remote read filter option
For special remote read endpoints which have only data for specific
queries, it is desired to limit the number of queries sent to the
configured remote read endpoint to reduce latency and performance
overhead.
2017-11-13 23:30:01 +01:00
Tobias Schmidt 434f0374f7 Refactor remote storage querier handling
* Decouple remote client from ReadRecent feature.
* Separate remote read filter into a small, testable function.
* Use storage.Queryable interface to compose independent
  functionalities.
2017-11-13 23:19:15 +01:00
Julius Volz 9f10c63cff
Fix remote read labelset corruption (#3456)
The labelsets returned from remote read are mutated in higher levels
(like seriesFilter.Labels()) and since the concreteSeriesSet didn't
return a copy, the external mutation affected the labelset in the
concreteSeries itself. This resulted in bizarre bugs where local and
remote series would show with identical label sets in the UI, but not be
deduplicated, since internally, a series might come to look like:

{__name__="node_load5", instance="192.168.1.202:12090", job="node_exporter", node="odroid", node="odroid"}

(note the repetition of the last label)
2017-11-12 00:47:47 +01:00
Krasi Georgiev 5d8f93a22a now using only github.com/gogo/protobuf
bumped all grpc-gateway packages to v1.2.2
updated and run  the denproto.sh script
2017-11-02 11:31:57 +00:00
Tom Wilkie 1af3ef431d s/TestRemoveLabels/TestSeriesSetFilter/ 2017-10-26 13:50:39 +01:00
Tom Wilkie 9c3c98e8de Revert "Port 'Don't disable HTTP keep-alives for remote storage connections.' to 2.0 (see #3173)"
This reverts commit 0997191b18.
2017-10-26 13:43:48 +01:00
Tom Wilkie 746752b946 Merge external labels in order. 2017-10-26 11:44:49 +01:00
Tom Wilkie 6e4d4ea402 Initialise some counters in remote storage API. 2017-10-26 11:09:45 +01:00
Tom Wilkie 2ae04d0e79 Add license header. 2017-10-26 11:09:16 +01:00
Tom Wilkie e8c264e47a Add comment. 2017-10-26 11:09:16 +01:00
Tom Wilkie ee011d906d Port remote read server to 2.0. 2017-10-26 11:09:14 +01:00
Bryan Boreham 0997191b18 Port 'Don't disable HTTP keep-alives for remote storage connections.' to 2.0 (see #3173)
Removes configurability introduced in #3160 in favour of hard-coding,
per advice from @brian-brazil.
2017-10-26 11:08:33 +01:00
Tom Wilkie 56820726fa Move a couple of the encoding/decoding functions into codec.go 2017-10-26 11:08:33 +01:00
Conor Broderick 08b7328669 Port Metric name validation to 2.0 (see #2975) 2017-10-26 11:08:33 +01:00
Tom Wilkie 8fe0212ff7 Port 'Make queue manager configurable.' to 2.0, see #2991 2017-10-26 11:08:33 +01:00
Tom Wilkie 3760f56c0c remote: Expose ClientConfig type (see #3165) 2017-10-26 11:08:33 +01:00
Tom Wilkie 16f71a7723 Port codec.go over form 1.8 branch. 2017-10-26 11:08:33 +01:00
Julius Volz 099df0c5f0 Migrate "golang.org/x/net/context" -> "context" (#3333)
In some places, where ctxhttp or gRPC are concerned, we still need to use the
old contexts.
2017-10-24 21:21:42 -07:00
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