CODEWITHSUNDEEP
javasoapexchangewebservicesews-managed-api
CaptainObv
CaptainObv

Reputation: 410

How can I monitor EWS SOAP messages relating to subscription creation

We have a spring java app using EWS to connect to our on prem 2016 Exchange server and 'stream' pulling emails. Every 30 minutes a new 30 minute subscription is made (via new thread). We assume old connection just expires.

When one instance is running in our environment, it works perfectly fine, but when two instances run, after some time one instance will eventually start throwing error about

You have exceeded the available concurrent connections for your account. Try again once your other requests have completed.

It seems like an issue which is then hit by throttling. I found that the Exchange servers config is:

EWSMaxConcurrency=27, MaxStreamingConcurrency=10,
HangingConnectionLimit=10

Our code previously didn't explicitly close connections and unsubscribe (was running fine without when one instance). We tried including both but the issue still persists and we noticed the close method for StreamingSubscriptionConnection throws error. The team that handles the Exchange server can find errors referencing the exceeding connection count error above, but nothing relating to the close connection error

...[m.e.w.d.n.StreamingSubscriptionConnection.close(349)]: java.lang.Exception: microsoft.exchange.webservices.data.notification.StreamingSubscriptionConnection

Currently we don't have much ability to make changes on the exchange server side. I'm not familiar with SOAP messages but I was planning to look into how to monitor them to see what inbound and outbound messages there are for some insights

For the service I set service.setTraceEnabled(true) and service.setTraceFlags(EnumSet.allOf(TraceFlags.class)

However I only see trace messages in console when an email arrives. I dont see any messages during start up when a subscription/connection is created

Can anyone help provide any advice on how I can monitor these subscription related messages?

I tried using SOAPUI but I'm having difficulty applying our server's WSDL. I considered using the Tunnelij plugin for intellij but I'm not too familiar with how to set it up either

My suspicion is that there is some intermittent latency issue on Exchange server side, perhaps response messages are not coming back in a timely manner, and this may be screwing up. I presume if I monitor these SOAP messages then I should see more than 10 requests to subscribe before that error appears

Upvotes: 0

Views: 148

Answers (1)

Glen Scales
Glen Scales

Reputation: 22032

The EWS Logs on the CAS (Client Access Server) should have details about the throttling issue. Are you using Impersonation in you Application if you not using Impersonation then the concurrent connections are charged against the account your using with Impersonation that get charged against the account your impersonating. The difference here is that a single user can have no more the 10 streaming subscriptions (unless you modify the web.config) if your using impersonation than you can scale your application to 1000's of users see https://github.com/MicrosoftDocs/office-developer-exchange-docs/blob/main/docs/exchange-web-services/how-to-maintain-affinity-between-group-of-subscriptions-and-mailbox-server.md

Upvotes: 0

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