From 8276ae54a12d9e919775c1d67fe7ad1a03710d94 Mon Sep 17 00:00:00 2001
From: zmstone <zmstone@gmail.com>
Date: Mon, 3 Jun 2024 11:04:38 +0200
Subject: [PATCH] chore: improve emqx boot script's compatibility check

Prior to this change, the command used to check installation
and os compatibility is done by starting a 'erl' process using
default flags. it might be unnecessarily expensive in large
VM instances.
In this change, we have added small enough +S +P and +Q number to
make lower the cost.
---
 bin/emqx     | 11 ++++++++++-
 bin/nodetool |  2 +-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/bin/emqx b/bin/emqx
index 1db57d7e8..b504ce8b4 100755
--- a/bin/emqx
+++ b/bin/emqx
@@ -337,6 +337,9 @@ compatiblity_info() {
   # set crash-dump bytes to zero to ensure no crash dump is generated when erl crashes
   env ERL_CRASH_DUMP_BYTES=0 "$BINDIR/$PROGNAME" \
     -noshell \
+    +S 2 \
+    +P 65536 \
+    +Q 65536 \
     -boot "$REL_DIR/start_clean" \
     -boot_var RELEASE_LIB "$ERTS_LIB_DIR/lib" \
     -eval "$COMPATIBILITY_CHECK"
@@ -408,6 +411,7 @@ remsh() {
             -setcookie "$COOKIE" \
             -hidden \
             -kernel net_ticktime "$TICKTIME" \
+            +P 65536 \
             +Q 65536 \
             +S 2 \
             $EPMD_ARGS
@@ -420,6 +424,7 @@ remsh() {
             --erl "-kernel net_ticktime $TICKTIME" \
             --erl "$EPMD_ARGS" \
             --erl "$NAME_TYPE $id" \
+            --erl "+P 65536" \
             --erl "+Q 65536" \
             --erl "+S 2" \
             --boot "$REL_DIR/start_clean"
@@ -1307,7 +1312,11 @@ case "${COMMAND}" in
               --boot "$REL_DIR/start_clean" \
               --boot-var RELEASE_LIB "$ERTS_LIB_DIR" \
               --vm-args "$REL_DIR/remote.vm.args" \
-              --erl "-start_epmd false -epmd_module ekka_epmd" \
+              --erl "-start_epmd false" \
+              --erl "-epmd_module ekka_epmd" \
+              --erl "+P 65536" \
+              --erl "+Q 65536" \
+              --erl "+S 2" \
               --rpc-eval "$NAME" "$@"
         else
             echo "EMQX node is not an Elixir node"
diff --git a/bin/nodetool b/bin/nodetool
index e1d45c88d..bfefd0ed9 100755
--- a/bin/nodetool
+++ b/bin/nodetool
@@ -1,6 +1,6 @@
 #!/usr/bin/env escript
 %% -*- mode: erlang;erlang-indent-level: 4;indent-tabs-mode: nil -*-
-%%! +Q 65536 +S 1
+%%! +P 65536 +Q 65536 +S 1
 %% ex: ft=erlang ts=4 sw=4 et
 %% -------------------------------------------------------------------
 %%