From b04832da844d1c9e4ce7f7ff387059fbd07f78d3 Mon Sep 17 00:00:00 2001
From: Valentin Bartenev <vbart@nginx.com>
Date: Wed, 24 Mar 2021 08:05:07 +0300
Subject: [PATCH] Disabled logging alerts to syslog.

It feels to be causing more harm than good, because syslog() can be blocking,
which is even more critical under resource exhaustion conditions when some
alerts are expected.
---
 src/nxt_app_log.c | 9 ++++++++-
 src/nxt_log.c     | 9 ++++++++-
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/src/nxt_app_log.c b/src/nxt_app_log.c
index 0ecd9aac..ae57c2a2 100644
--- a/src/nxt_app_log.c
+++ b/src/nxt_app_log.c
@@ -19,7 +19,10 @@ static u_char *nxt_log_debug_time(u_char *buf, nxt_realtime_t *now,
 void nxt_cdecl
 nxt_log_time_handler(nxt_uint_t level, nxt_log_t *log, const char *fmt, ...)
 {
-    u_char             *p, *syslogmsg, *end;
+    u_char             *p, *end;
+#if 0
+    u_char             *syslogmsg;
+#endif
     va_list            args;
     nxt_thread_t       *thr;
     nxt_time_string_t  *time_cache;
@@ -34,7 +37,9 @@ nxt_log_time_handler(nxt_uint_t level, nxt_log_t *log, const char *fmt, ...)
 
     p = nxt_thread_time_string(thr, time_cache, msg);
 
+#if 0
     syslogmsg = p;
+#endif
 
 #if 0
     nxt_fid_t    fid;
@@ -79,6 +84,7 @@ nxt_log_time_handler(nxt_uint_t level, nxt_log_t *log, const char *fmt, ...)
 
     (void) nxt_write_console(nxt_stderr, msg, p - msg);
 
+#if 0
     if (level == NXT_LOG_ALERT) {
         *(p - nxt_length("\n")) = '\0';
 
@@ -88,6 +94,7 @@ nxt_log_time_handler(nxt_uint_t level, nxt_log_t *log, const char *fmt, ...)
          */
         nxt_write_syslog(LOG_ALERT, syslogmsg);
     }
+#endif
 }
 
 
diff --git a/src/nxt_log.c b/src/nxt_log.c
index 1c666961..58756816 100644
--- a/src/nxt_log.c
+++ b/src/nxt_log.c
@@ -66,7 +66,10 @@ nxt_log_set_ctx(nxt_log_t *log, nxt_log_ctx_handler_t handler, void *ctx)
 void nxt_cdecl
 nxt_log_handler(nxt_uint_t level, nxt_log_t *log, const char *fmt, ...)
 {
-    u_char   *p, *syslogmsg, *end;
+    u_char   *p, *end;
+#if 0
+    u_char   *syslogmsg;
+#endif
     va_list  args;
     u_char   msg[NXT_MAX_ERROR_STR];
 
@@ -79,7 +82,9 @@ nxt_log_handler(nxt_uint_t level, nxt_log_t *log, const char *fmt, ...)
         *p++ = ' ';
     }
 
+#if 0
     syslogmsg = p;
+#endif
 
     p = nxt_sprintf(p, end, (log->ident != 0) ? "[%V] *%D " : "[%V] ",
                     &nxt_log_levels[level], log->ident);
@@ -100,6 +105,7 @@ nxt_log_handler(nxt_uint_t level, nxt_log_t *log, const char *fmt, ...)
 
     (void) nxt_write_console(nxt_stderr, msg, p - msg);
 
+#if 0
     if (level == NXT_LOG_ALERT) {
         *(p - nxt_length("\n")) = '\0';
 
@@ -109,4 +115,5 @@ nxt_log_handler(nxt_uint_t level, nxt_log_t *log, const char *fmt, ...)
          */
         nxt_write_syslog(LOG_ALERT, syslogmsg);
     }
+#endif
 }