From b1e9525cf0080d45321d789f7c7efc6c96ffebae Mon Sep 17 00:00:00 2001
From: Tom Molesworth <tom@deriv.com>
Date: Thu, 5 Sep 2024 12:01:35 +0800
Subject: [PATCH] Handle stream creation race condition

---
 lib/Myriad/Transport/Redis.pm | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/lib/Myriad/Transport/Redis.pm b/lib/Myriad/Transport/Redis.pm
index d6304ba5..ec8b1ecf 100644
--- a/lib/Myriad/Transport/Redis.pm
+++ b/lib/Myriad/Transport/Redis.pm
@@ -451,7 +451,15 @@ Then destroy that init consumer group.
 
 async method create_stream ($stream) {
     await $self->create_group($stream, 'INIT', '$', 1);
-    await $self->remove_group($stream, 'INIT');
+    try {
+        await $self->remove_group($stream, 'INIT');
+    } catch ($e) {
+        # If we have multiple instances, there's a race condition between creating the group
+        # and another instance trying to delete it before we get there. Ignore errors when
+        # that happens - we don't care who deleted the group, just that it goes away - but
+        # rethrow any other errors.
+        die $e unless $e =~ /NOGROUP/;
+    }
     $log->tracef('created a Redis stream: %s', $stream);
 }