GRPC::Unavailable: Failed parsing HTTP/2 error on large diffs

~Conversation: #222 (closed)

Blocks: #209 (closed)

Reported in Sentry: https://sentry.gitlap.com/gitlab/staginggitlabcom/issues/30273/

Reported in Kibana: https://log.gitlap.com/goto/a682bcda100256c813a2de23c43cbddd

ActionView::Template::Error
14:Failed parsing HTTP/2


GRPC::Unavailable
14:Failed parsing HTTP/2

On staging, this happens every time at the URL https://staging.gitlab.com/gitlab-org/gitlab-ce/commit/452c076a34cc11cc97f4b1c3113e86ce4367e055 which is a particularly large diff, which means that this might be releated to #229 (closed).

At present, we're unable to recreate this issue.

@ahmadsherif will look to recreate the problem so that we can figure out whether the RPC redesign that comes out of #229 (closed) will fix this too.

Until we have more details we will not test in production.