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The following error occurs when running the sandbox:

io.grpc.netty.NettyServerHandler onStreamError
WARNING: Stream Error
io.netty.handler.codec.http2.Http2Exception$HeaderListSizeException: Header size exceeded max allowed size (8192)

What could the cause of this be?

stefanobaghino
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arjun a
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  • It's quite difficult to pinpoint a specific cause, can you be more specific about the conditions that cause the error to occur? – stefanobaghino Jan 23 '20 at 09:55
  • when am running more than 4 trackers – arjun a Jan 24 '20 at 04:44
  • Unfortunately that doesn't seem to be a condition that causes such error, generally speaking. If you could make a minimal, reproducible example it would be much easier for me to help you. Here are some suggestions on how to improve your questions on StackOverflow. https://stackoverflow.com/help/minimal-reproducible-example – stefanobaghino Jan 24 '20 at 13:27

1 Answers1

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I have seen this error numerous times, and it is a consequence of having a transaction failure in a complex DAML model/transaction when running on the Sandbox. When you experience a transaction failure (fetch/exercise an inactive contract, lookupByKey returned a stale cid, head [], divide-by-zero, etc) the sandbox helpfully tries to provide transaction trace information in the error result.

This is normally fine for relatively simple models. With more complex models this trace can exceed the maximum header size producing the error you see. When this happens I have found the trace in the sandbox.log file, sometimes along with other errors that help explain what is going on.

The trace is an unformatted dump, so it can take a bit of effort to decode manually, but I have done it many times myself and the information I needed to identify the issue has always been there —— and to be honest, generally just knowing the choice I was exercising + the specific class of error is normally enough to point me in the right direction.

I believe there is some tooling being built to help with this sort of diagnosis; however, I don't know how advanced the work on that is.

Recurse
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