Couchbase Internal ComputeHash Thread Hang Issue


#1

We have a web application running under heavy load and we hold frequently used data in couchbase for performance purposes.We have a cluster with six nodes and we are dealing with a fantastic problem these days.We detected excessive CPU usage on one of our servers and got a dump.When we examine this dump file, there is a thread that is hanging for 30 minutes.It seems like this couchbase is trying to get vbucket.Any ideas?

00000100b184aff0 000007feed4191e9 System.Security.Cryptography.HashAlgorithm.ComputeHash(Byte[])
00000100b184b030 000007fe8f983167 Couchbase.Core.Buckets.VBucketKeyMapper.GetIndex(System.String)
00000100b184b0a0 000007fe8f983253 Couchbase.Core.Buckets.VBucketKeyMapper.MapKey(System.String)
00000100b184b0f0 000007fe8f9839d8 Couchbase.Core.Buckets.VBucketKeyMapper.MapKey(System.String, UInt32)
00000100b184b120 000007fe8f9835aa Couchbase.Core.Buckets.CouchbaseRequestExecuter.SendWithRetry[[System.__Canon, mscorlib]](Couchbase.IO.Operations.IOperation`1)
00000100b184b190 000007fe8f9bc680 Couchbase.CouchbaseBucket.Upsert[[System.__Canon, mscorlib]](Couchbase.IDocument`1)

#2

Hi @aatar

Can you provide the SDK and server versions you’re using? Also, are you using .NET full framework or .NET Core?

From your stack trace, it indicates the HashAlgorithm.ComputeHash call is hanging, which is a MS library.

Thanks


#3

It’s definitely not a problem with CouchBase. I just wonder if anyone who has experience with CouchBase has encountered such a thing.We are using full .net framework and Couchbase Client SDK version is 2.3.8.0;


#4

Unfortunately, no I’ve not come across this before.