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https://issues.apache.org/jira/browse/TINKERPOP-2288?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16957660#comment-16957660
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Some One commented on TINKERPOP-2288:
-------------------------------------

For everyone who is waiting for a fix, the following work around with polly 
does the trick for us, although it is not ideal. We already handled the '429 
Too Many Requests' exceptions before, but now also added the handling of 
ConnectionPoolBusyExceptions and ServerUnavailableExceptions where we 
immediately create a new client (by calling the SetupGremlinClient method 
below).

 

{{ResultSet<dynamic> response = await Polly.Policy}}
{{ .Handle<ResponseException>(exception => exception.CosmosDbStatusCode() == 
RetryAfterStatusCode)}}
{{ .Or<ConnectionPoolBusyException>()}}
{{ .Or<ServerUnavailableException>()}}
{{ .WaitAndRetryAsync(}}
{{ retryCount: 10,}}
{{ sleepDurationProvider: (attempt, exception, _) =>}}
{{ {}}
{{ if (exception is ResponseException responseException)}}
{{ return responseException.CosmosDbRetryAfter();}}{{// In case this is a 
connection issue, we try again immediately}}
{{ return TimeSpan.Zero;}}
{{ },}}
{{ onRetryAsync: (exception, waitTime, attempt, _) =>}}
{{ {}}
{{ // In case this is a connection issue we reset the client}}
{{ if (exception is ConnectionPoolBusyException || exception is 
ServerUnavailableException)}}
{{ {}}
{{ _log.LogWarning($"Resetting the GremlinClient after experiencing an 
'\{exception.GetType()}'");}}
{{ SetupGremlinClient();}}
{{ }}}
{{ return Task.CompletedTask;}}
{{ })}}
{{ .ExecuteAsync(() => _gremlinClient.SubmitAsync<dynamic>(query));}}

 

{{private void SetupGremlinClient()}}
{{ {}}
{{ var stopWatch = new Stopwatch();}}
{{ stopWatch.Start();}}{{var settings = new 
ConnectionPoolSettings\{MaxInProcessPerConnection = 64, PoolSize = 8};// 
Default MacInProcessPerConnection = 32, PoolSize = 4}}{{_gremlinClient = new 
GremlinClient(_gremlinServer, new GraphSON2Reader(), new GraphSON2Writer(),}}
{{ GremlinClient.GraphSON2MimeType,settings}}
{{ ); }}
{{ stopWatch.Stop();}}{{_log.LogInformation($"Setting up GremlinClient with 
PoolSize of \{settings.PoolSize} and MaxInProcessPerConnection of 
\{settings.MaxInProcessPerConnection} took 
\{stopWatch.ElapsedMilliseconds}ms");}}
{{ }}}

> Get ConnectionPoolBusyException and then ServerUnavailableExceptions
> --------------------------------------------------------------------
>
>                 Key: TINKERPOP-2288
>                 URL: https://issues.apache.org/jira/browse/TINKERPOP-2288
>             Project: TinkerPop
>          Issue Type: Bug
>          Components: dotnet
>    Affects Versions: 3.4.1
>         Environment: Gremlin.Net 3.4.1
> Microsoft.NetCore.App 2.2
> Azure Cosmos DB
>            Reporter: patrice huot
>            Priority: Critical
>
> I am using .Net core Gremlin API  query Cosmos DB.
> From time to time we are getting an error saying that no connection is 
> available and then the server become unavailable. When this is occurring we 
> need to restart the server. It looks like the connections are not released 
> properly and become unavailable forever.
> We have configured the pool size to 50 and the MaxInProcessPerConnection to 
> 32 (Which I guess should be sufficient).
> To diagnose the issue, Is there a way to access diagnostic information on the 
> connection pool in order to know how many connections are open and how many 
> processes are running in each connection?
> I would like to be able to monitor the connections usage to see if they are 
> about to be exhausted and to see if the number of used connections is always 
> increasing or of the connection lease is release when the queries completes?
> As a work around, Is there a way we can access this information from the code 
> so that I can catch those scenario and create logic that re-initiate the 
> connection pool?
>  
>  



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