memgraph/docs/user_technical/installation.md
florijan d9503d6b65 Flags cleanup and QueryEngine removal
Summary:
I started with cleaning flags up (removing unused ones, documenting undocumented ones). There were some flags to remove in `QueryEngine`. Seeing how we never use hardcoded queries (AFAIK last Mislav's testing also indicated they aren't faster then interpretation), when removing those unused flags the `QueryEngine` becomes obsolete. That means that a bunch of other stuff becomes obsolete, along with the hardcoded queries. So I removed it all (this has been discussed and approved on the daily).

Some flags that were previously undocumented in `docs/user_technical/installation` are now documented. The following flags are NOT documented and in my opinion should not be displayed when starting `./memgraph --help` (@mferencevic):
```
query_vertex_count_to_expand_existsing (from rule_based_planner.cpp)
query_max_plans (rule_based_planner.cpp)
```

If you think that another organization is needed w.r.t. flag visibility, comment.

@teon.banek: I had to remove some stuff from CMakeLists to make it buildable. Please review what I removed and clean up if necessary if/when this lands. If the needed changes are minor, you can also comment.

Reviewers: buda, mislav.bradac, teon.banek, mferencevic

Reviewed By: buda, mislav.bradac

Subscribers: pullbot, mferencevic, teon.banek

Differential Revision: https://phabricator.memgraph.io/D825
2017-09-22 17:03:45 +02:00

4.6 KiB

Installation

Memgraph is a 64-bit Linux compatible database management system. For the purpose of Alpha testing Memgraph has been packed into a Docker image based on Ubuntu 16.04. Before proceeding with the installation, please install the Docker engine on your system. Instructions how to install Docker can be found on the official Docker website. Memgraph Docker image was built with Docker version 1.12 and should be compatible with all latter versions.

Docker Import

After a successful download the Memgraph Docker image can be imported into Docker:

docker load -i /path/to/memgraph_alpha_v0.7.0.tar.gz

Image Configuration & Running Memgraph

Memgraph can be started by executing:

docker run -it -p 7687:7687 memgraph_alpha_v0.7.0

The -it option enables displaying Memgraph's logs inside the current shell. The -p option is used to specify the port on which Memgraph will listen for requests. Memgraph uses the Bolt protocol for network communication, which uses port 7687 by default.

It is recommended to perform some additional Docker configuration. Memgraph is currently an in-memory database management system, but it periodically stores all data to the hard drive. These storages are referred to as snapshots and are used for recovering data in case of a restart. When starting Memgraph, a folder for snapshots needs to be created and mounted on the host file system. It is also recommended to run the Docker container in the background. On a Linux system all of that can be achieved with the following shell commands:

# Create the snapshots folder on the host.
mkdir -p memgraph
# Docker expects full path to the created folder.
FULL_OUTPUT_PATH=$PWD/memgraph
# Run Memgraph.
docker run -d -p 7687:7687 -v ${FULL_OUTPUT_PATH}:/var/lib/memgraph --name <memgraph_docker_container_name> memgraph_alpha_v0.7.0

In the commands above -d means that the container will be detached (run in the background). -v mounts a host folder to a path inside the Docker container. The output folder contains Memgraph's periodical snapshots and log file. The log file should be uploaded to Memgraph's issue tracking system in case of an error. With --name a custom name for the container can be set (useful for easier container management). <memgraph_docker_container_name> could be any convenient name e.g. memgraph_alpha.

Memgraph Configuration Parameters

Memgraph can be configured with a number of command-line parameters. The parameters should be appended to the end of the docker run command in the --param-name=param-value format. Following is a list of available parameters:

Name Type Default Description
--interface string "0.0.0.0" Communication port on which to listen.
--port integer 7687 Communication port on which to listen.
--num-workers integer CPU count1 Number of Memgraph worker threads.
--log-file string "memgraph.log" Path to where the log should be stored.
--snapshot-cycle-sec integer 300 Interval (seconds) between database snapshots.
Value of -1 turns taking snapshots off.
--snapshot-max-retained integer 3 Number of retained snapshots.
Value -1 means without limit.
--snapshot-on-exit bool false Make a snapshot when closing Memgraph.
--snapshot-recover-on-startup bool false Recover the database on startup using the last
stored snapshot.
--query-execution-time-sec integer 180 Maximum allowed query execution time.
Queries exceeding this limit will be aborted. Value of -1 means no limit.
--memory-warning-threshold integer 1024 Memory warning threshold, in MB. If Memgraph detects there is less available RAM available it will log a warning. Set to 0 to disable.
--ast-cache bool true Use AST caching.
--query-plan-cache bool Cache generated query plans.
--query-plan-cache-ttl int 60 Time to live for cached query plans, in seconds.
--query-cost-planner bool true Use the cost-estimating query planner.

To find more about how to execute queries on Memgraph please proceed to Quick Start.

Cleanup

Status and Memgraph's logging messages can be checked with:

docker ps -a
docker logs -f <memgraph_docker_container_name>

Memgraph and its Docker container can be stopped with:

docker stop <memgraph_docker_container_name>

After the container has stopped, it can be removed by executing:

docker rm <memgraph_docker_container_name>

  1. Maximum number of concurrent executions on the current CPU. ↩︎