From 684ebf092847dacfe94c37e85c6474535619484e Mon Sep 17 00:00:00 2001
From: Nick Cabatoff <ncabatoff@hashicorp.com>
Date: Fri, 16 Apr 2021 15:55:05 -0400
Subject: [PATCH] Don't cut off stack traces at 32MB. (#11364)

---
 changelog/11364.txt | 3 +++
 command/server.go   | 6 +++---
 2 files changed, 6 insertions(+), 3 deletions(-)
 create mode 100644 changelog/11364.txt

diff --git a/changelog/11364.txt b/changelog/11364.txt
new file mode 100644
index 000000000..64fae590a
--- /dev/null
+++ b/changelog/11364.txt
@@ -0,0 +1,3 @@
+```release-note:improvement
+core: allow arbitrary length stack traces upon receiving SIGUSR2 (was 32MB)
+```
diff --git a/command/server.go b/command/server.go
index 1a5fc8240..974c914f9 100644
--- a/command/server.go
+++ b/command/server.go
@@ -14,6 +14,7 @@ import (
 	"os"
 	"path/filepath"
 	"runtime"
+	"runtime/pprof"
 	"sort"
 	"strconv"
 	"strings"
@@ -1969,9 +1970,8 @@ CLUSTER_SYNTHESIS_COMPLETE:
 			}
 
 		case <-c.SigUSR2Ch:
-			buf := make([]byte, 32*1024*1024)
-			n := runtime.Stack(buf[:], true)
-			c.logger.Info("goroutine trace", "stack", string(buf[:n]))
+			logWriter := c.logger.StandardWriter(&hclog.StandardLoggerOptions{})
+			pprof.Lookup("goroutine").WriteTo(logWriter, 2)
 		}
 	}