d4b9fe801f
When appending to the head and a chunk is full it is flushed to the disk and m-mapped (memory mapped) to free up memory Prom startup now happens in these stages - Iterate the m-maped chunks from disk and keep a map of series reference to its slice of mmapped chunks. - Iterate the WAL as usual. Whenever we create a new series, look for it's mmapped chunks in the map created before and add it to that series. If a head chunk is corrupted the currpted one and all chunks after that are deleted and the data after the corruption is recovered from the existing WAL which means that a corruption in m-mapped files results in NO data loss. [Mmaped chunks format](https://github.com/prometheus/prometheus/blob/master/tsdb/docs/format/head_chunks.md) - main difference is that the chunk for mmaping now also includes series reference because there is no index for mapping series to chunks. [The block chunks](https://github.com/prometheus/prometheus/blob/master/tsdb/docs/format/chunks.md) are accessed from the index which includes the offsets for the chunks in the chunks file - example - chunks of series ID have offsets 200, 500 etc in the chunk files. In case of mmaped chunks, the offsets are stored in memory and accessed from that. During WAL replay, these offsets are restored by iterating all m-mapped chunks as stated above by matching the series id present in the chunk header and offset of that chunk in that file. **Prombench results** _WAL Replay_ 1h Wal reply time 30% less wal reply time - 4m31 vs 3m36 2h Wal reply time 20% less wal reply time - 8m16 vs 7m _Memory During WAL Replay_ High Churn: 10-15% less RAM - 32gb vs 28gb 20% less RAM after compaction 34gb vs 27gb No Churn: 20-30% less RAM - 23gb vs 18gb 40% less RAM after compaction 32.5gb vs 20gb Screenshots are in [this comment](https://github.com/prometheus/prometheus/pull/6679#issuecomment-621678932) Signed-off-by: Ganesh Vernekar <cs15btech11018@iith.ac.in> |
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|---|---|---|
| .circleci | ||
| .github | ||
| cmd | ||
| config | ||
| console_libraries | ||
| consoles | ||
| discovery | ||
| docs | ||
| documentation | ||
| notifier | ||
| pkg | ||
| prompb | ||
| promql | ||
| rules | ||
| scrape | ||
| scripts | ||
| storage | ||
| template | ||
| tsdb | ||
| util | ||
| vendor | ||
| web | ||
| .dockerignore | ||
| .gitignore | ||
| .golangci.yml | ||
| .promu.yml | ||
| CHANGELOG.md | ||
| code-of-conduct.md | ||
| CONTRIBUTING.md | ||
| Dockerfile | ||
| fuzzit.sh | ||
| go.mod | ||
| go.sum | ||
| LICENSE | ||
| MAINTAINERS.md | ||
| Makefile | ||
| Makefile.common | ||
| NOTICE | ||
| README.md | ||
| RELEASE.md | ||
| VERSION | ||
Prometheus
Visit prometheus.io for the full documentation, examples and guides.
Prometheus, a Cloud Native Computing Foundation project, is a systems and service monitoring system. It collects metrics from configured targets at given intervals, evaluates rule expressions, displays the results, and can trigger alerts if some condition is observed to be true.
Prometheus's main distinguishing features as compared to other monitoring systems are:
- a multi-dimensional data model (timeseries defined by metric name and set of key/value dimensions)
- a flexible query language to leverage this dimensionality
- no dependency on distributed storage; single server nodes are autonomous
- timeseries collection happens via a pull model over HTTP
- pushing timeseries is supported via an intermediary gateway
- targets are discovered via service discovery or static configuration
- multiple modes of graphing and dashboarding support
- support for hierarchical and horizontal federation
Architecture overview
Install
There are various ways of installing Prometheus.
Precompiled binaries
Precompiled binaries for released versions are available in the download section on prometheus.io. Using the latest production release binary is the recommended way of installing Prometheus. See the Installing chapter in the documentation for all the details.
Debian packages are available.
Docker images
Docker images are available on Quay.io or Docker Hub.
You can launch a Prometheus container for trying it out with
$ docker run --name prometheus -d -p 127.0.0.1:9090:9090 prom/prometheus
Prometheus will now be reachable at http://localhost:9090/.
Building from source
To build Prometheus from the source code yourself you need to have a working Go environment with version 1.13 or greater installed. You will also need to have Node.js and Yarn installed in order to build the frontend assets.
You can directly use the go tool to download and install the prometheus
and promtool binaries into your GOPATH:
$ go get github.com/prometheus/prometheus/cmd/...
$ prometheus --config.file=your_config.yml
However, when using go get to build Prometheus, Prometheus will expect to be able to
read its web assets from local filesystem directories under web/ui/static and
web/ui/templates. In order for these assets to be found, you will have to run Prometheus
from the root of the cloned repository. Note also that these directories do not include the
new experimental React UI unless it has been built explicitly using make assets or make build.
An example of the above configuration file can be found here.
You can also clone the repository yourself and build using make build, which will compile in
the web assets so that Prometheus can be run from anywhere:
$ mkdir -p $GOPATH/src/github.com/prometheus
$ cd $GOPATH/src/github.com/prometheus
$ git clone https://github.com/prometheus/prometheus.git
$ cd prometheus
$ make build
$ ./prometheus --config.file=your_config.yml
The Makefile provides several targets:
- build: build the
prometheusandpromtoolbinaries (includes building and compiling in web assets) - test: run the tests
- test-short: run the short tests
- format: format the source code
- vet: check the source code for common errors
- docker: build a docker container for the current
HEAD
React UI Development
For more information on building, running, and developing on the new React-based UI, see the React app's README.md.
More information
- The source code is periodically indexed: Prometheus Core.
- You will find a CircleCI configuration in
.circleci/config.yml. - See the Community page for how to reach the Prometheus developers and users on various communication channels.
Contributing
Refer to CONTRIBUTING.md
License
Apache License 2.0, see LICENSE.