Make maximum number of Erlang processes configurable via env

This property is essential for nodes that need to handle many
connections / channels / queues.

Related to #1513

Author: gerhard

scripts/rabbitmq-env

@@ -87,8 +87,11 @@ DEFAULT_SCHEDULER_BIND_TYPE="db"
 DEFAULT_DISTRIBUTION_BUFFER_SIZE=128000
 [ "x" = "x$RABBITMQ_DISTRIBUTION_BUFFER_SIZE" ] && RABBITMQ_DISTRIBUTION_BUFFER_SIZE=${DEFAULT_DISTRIBUTION_BUFFER_SIZE}
 
+DEFAULT_MAX_NUMBER_OF_PROCESSES=1048576
+[ "x" = "x$RABBITMQ_MAX_NUMBER_OF_PROCESSES" ] && RABBITMQ_MAX_NUMBER_OF_PROCESSES=="${DEFAULT_MAX_NUMBER_OF_PROCESSES}"
+
 ## Common server defaults
-SERVER_ERL_ARGS="+P 1048576 +t 5000000 +stbt $RABBITMQ_SCHEDULER_BIND_TYPE +zdbbl $RABBITMQ_DISTRIBUTION_BUFFER_SIZE"
+SERVER_ERL_ARGS="+P $RABBITMQ_MAX_NUMBER_OF_PROCESSES +t 5000000 +stbt $RABBITMQ_SCHEDULER_BIND_TYPE +zdbbl $RABBITMQ_DISTRIBUTION_BUFFER_SIZE"
 
 # We save the current value of $RABBITMQ_PID_FILE in case it was set by
 # an init script. If $CONF_ENV_FILE overrides it again, we must ignore

test/rabbitmq-env.bats

@@ -1,19 +1,29 @@
-@test "can set RABBITMQ_SCHEDULER_BIND_TYPE from rabbitmq-env.conf" {
+@test "can configure RABBITMQ_SCHEDULER_BIND_TYPE" {
     declare -r scripts_dir="$BATS_TEST_DIRNAME/../scripts"
     export RABBITMQ_SCRIPTS_DIR="$scripts_dir"
     export RABBITMQ_CONF_ENV_FILE="$BATS_TMPDIR/rabbitmq-env.conf"
     echo 'RABBITMQ_SCHEDULER_BIND_TYPE=u' > "$RABBITMQ_CONF_ENV_FILE"
     source "$scripts_dir/rabbitmq-env"
-    echo "expect RABBITMQ_SERVER_ERL_ARGS to contain '+stbt u' but got '$SERVER_ERL_ARGS'" 
+    echo "expected RABBITMQ_SERVER_ERL_ARGS to contain '+stbt u', but got: $RABBITMQ_SERVER_ERL_ARGS"
     [[ $RABBITMQ_SERVER_ERL_ARGS == *+stbt\ u* ]]
 }
 
-@test "can set RABBITMQ_DISTRIBUTION_BUFFER_SIZE from rabbitmq-env.conf" {
+@test "can configure RABBITMQ_DISTRIBUTION_BUFFER_SIZE" {
     declare -r scripts_dir="$BATS_TEST_DIRNAME/../scripts"
     export RABBITMQ_SCRIPTS_DIR="$scripts_dir"
     export RABBITMQ_CONF_ENV_FILE="$BATS_TMPDIR/rabbitmq-env.conf"
     echo 'RABBITMQ_DISTRIBUTION_BUFFER_SIZE=123456' > "$RABBITMQ_CONF_ENV_FILE"
     source "$scripts_dir/rabbitmq-env"
-    echo "expect RABBITMQ_SERVER_ERL_ARGS to contain '+zdbbl 123456' but got '$SERVER_ERL_ARGS'" 
+    echo "expected RABBITMQ_SERVER_ERL_ARGS to contain '+zdbbl 123456', but got: $RABBITMQ_SERVER_ERL_ARGS"
     [[ $RABBITMQ_SERVER_ERL_ARGS == *+zdbbl\ 123456* ]]
 }
+
+@test "can configure RABBITMQ_MAX_NUMBER_OF_PROCESSES" {
+    declare -r scripts_dir="$BATS_TEST_DIRNAME/../scripts"
+    export RABBITMQ_SCRIPTS_DIR="$scripts_dir"
+    export RABBITMQ_CONF_ENV_FILE="$BATS_TMPDIR/rabbitmq-env.conf"
+    echo 'RABBITMQ_MAX_NUMBER_OF_PROCESSES=2000000' > "$RABBITMQ_CONF_ENV_FILE"
+    source "$scripts_dir/rabbitmq-env"
+    echo "expected RABBITMQ_SERVER_ERL_ARGS to contain '+P 2000000', but got: $RABBITMQ_SERVER_ERL_ARGS"
+    [[ $RABBITMQ_SERVER_ERL_ARGS == *+P\ 2000000* ]]
+}