Fill the alpha.conf with all settings and document them

Summary:
This should be the basis for default configuration that is to be shipped
in release builds/packages.

Reviewers: mislav.bradac, florijan, buda, mferencevic

Reviewed By: florijan

Subscribers: pullbot

Differential Revision: https://phabricator.memgraph.io/D851

CMakeLists.txt

@@ -317,8 +317,8 @@ if (MEMGRAPH)
     install(PROGRAMS ${CMAKE_BINARY_DIR}/${MEMGRAPH_BUILD_NAME}
             DESTINATION bin RENAME memgraph)
     # Install the config file.
-    install(FILES ${CMAKE_SOURCE_DIR}/config/alpha.conf
-            DESTINATION /etc/memgraph RENAME config)
+    install(FILES ${CMAKE_SOURCE_DIR}/config/community.conf
+            DESTINATION /etc/memgraph RENAME memgraph.conf)
     # Create empty directories for default location of snapshots and logs.
     install(CODE "file(MAKE_DIRECTORY \$ENV{DESTDIR}/var/log/memgraph
                        \$ENV{DESTDIR}/var/lib/memgraph/snapshots)")

config/alpha.conf

@@ -1,28 +0,0 @@
-# MEMGRAPH DEFAULT ALPHA CONFIG
-
-# NOTE: all paths are relative to the run folder
-# (where the executable is run)
-
-# path to the folder with snapshots
---snapshot-directory=/var/lib/memgraph/snapshots
-
-# snapshot cycle interval
-# if set to -1 the snapshooter will not run
---snapshot-cycle-sec=300
-
-# create snapshot disabled on db exit
---snapshot-on-exit=true
-
-# max number of snapshots which will be kept on the disk at some point
-# if set to -1 the max number of snapshots is unlimited
---snapshot-max-retained=3
-
-# true if the database should recover the latest snapshot on startup
---snapshot-recover-on-startup=true
-
-# cleaning cycle interval
-# if set to -1 the GC will not run
---gc-cycle-sec=30
-
-# path to where the log should be stored
---log-file=/var/log/memgraph/memgraph.log

config/community.conf

@@ -0,0 +1,89 @@
+# Default Memgraph Configuration
+#
+# This is the default configuration for memgraph. Settings from this file will
+# be overridden by a configuration file in '$HOME/.memgraph/config', so you can
+# keep this file intact. Additional configuration can be specified in a file
+# pointed to by 'MEMGRAPH_CONFIG' environment variable or by passing arguments
+# on the command line.
+#
+# Each configuration setting is of the form: '--setting-name=value'.
+
+## Database
+
+# IP address the server should listen on.
+--interface=0.0.0.0
+
+# Port the server should listen on.
+--port=7687
+
+# Number of workers used by the Memgraph server. By default, this will be the
+# number of processing units available on the machine.
+# --num-workers=8
+
+# Interval, in seconds, when the garbage collection (GC) should run. GC is used
+# for releasing memory that is no longer needed. For example, deleted graph
+# elements which cannot be seen by any running or new transactions. If set to
+# -1 the GC will never run (use with caution, memory will never get released).
+--gc-cycle-sec=30
+
+# If Memgraph detects there is less available RAM than the given number in MB,
+# it will log a warning.
+--memory-warning-threshold=1024
+
+## Query
+#
+# Various settings related to openCypher query execution.
+
+# Maximum allowed query execution time, in seconds. Any queries exceeding this
+# limit will be aborted. Setting to -1 removes the limit.
+--query-execution-time-sec=30
+
+# Cache generated query execution plans. This speeds up planning repeated
+# queries which produce multiple complex execution plans. The downside is that
+# some executions may use inferior plans if the database state changed. To
+# disable caching, set to false.
+#--query-plan-cache=false
+
+# Time to live for cached query plans, in seconds. This tries to minimize the
+# downside of caching by evicting old plans after the given time.
+#--query-plan-cache-ttl=60
+
+## Snapshot
+#
+# Snapshots store the database state to persistent storage. Snapshots are
+# taken in intervals and can be used to restore the database to a previous
+# state.
+
+# Interval of taking snapshots, in seconds. If set to -1, snapshot feature
+# will be turned off.
+--snapshot-cycle-sec=300
+
+# Create a snapshot when closing Memgraph.
+--snapshot-on-exit=true
+
+# Path to the directory where snapshots will be stored.
+--snapshot-directory=/var/lib/memgraph/snapshots
+
+# Maximum number of kept snapshots. Old snapshots will be deleted to make room
+# for new ones. If set to -1, the number of kept snapshots is unlimited.
+--snapshot-max-retained=3
+
+# Recover the database from the latest snapshot on startup.
+--snapshot-recover-on-startup=true
+
+## Logging
+
+# Path to where the log should be stored.
+--log-file=/var/log/memgraph/memgraph.log
+
+# If true, log messages will go to stderr in addition to logfiles.
+#--also-log-to-stderr=true
+
+## Additional Configuration Inclusion
+
+# Include additional configuration from this file. Settings with the same name
+# will override previously read values. Note, that reading the configuration,
+# which called '--flag-file' will continue after inclusion. Therefore, settings
+# after '--flag-file' may override the included ones.
+#--flag-file=another.conf
+

src/memgraph_bolt.cpp

@@ -47,13 +47,13 @@ DEFINE_uint64(memory_warning_threshold, 1024,
               "disable.");
 
 // Load flags in this order, the last one has the highest priority:
-// 1) /etc/memgraph/config
+// 1) /etc/memgraph/memgraph.conf
 // 2) ~/.memgraph/config
 // 3) env - MEMGRAPH_CONFIG
 // 4) command line flags
 
 void load_config(int &argc, char **&argv) {
-  std::vector<fs::path> configs = {fs::path("/etc/memgraph/config")};
+  std::vector<fs::path> configs = {fs::path("/etc/memgraph/memgraph.conf")};
   if (getenv("HOME") != nullptr)
     configs.emplace_back(fs::path(getenv("HOME")) /
                          fs::path(".memgraph/config"));