# Aerospike C# client Error Code -3 **URL:** \ **Category:** C# Client\ **Created:** [May 15, 2017, 12:47pm UTC](https://discuss.aerospike.com/t/aerospike-c-client-error-code-3/4160 "2017-05-15T12:47:16Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Igor](https://avatars.discourse-cdn.com/v4/letter/i/dec6dc/32.png) [@Igor](https://discuss.aerospike.com/u/Igor)\ **Post date:** [May 15, 2017, 12:47pm UTC](https://discuss.aerospike.com/t/aerospike-c-client-error-code-3/4160/1 "2017-05-15T12:47:16Z")
Hi. We have a problem with aerospike client on c# (we think that it is a problem with client). We use version 3.4.2. When we create a lot of task (c# tasks) (list of tasks) with calling async aerospike client sometimes we get an error: Aerospike.Client.AerospikeException: Error Code -3: Invalid node. When we use not too much tasks - all works fine. Also should say, that we do not use a cluster on server side, use only a single node. Could you please explain what such error mean and how we could fix it? ---
**Author:** ![Albot](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.aerospike.com/albot/32/2076_2.png) [@Albot](https://discuss.aerospike.com/u/Albot)\ **Post date:** [May 15, 2017, 11:31pm UTC](https://discuss.aerospike.com/t/aerospike-c-client-error-code-3/4160/2 "2017-05-15T23:31:18Z")
Me too! I haven’t quite tied it back to a sync call volume though… Are you subscribed to the Aerospike log? [http://www.aerospike.com/docs/client/csharp/usage/logging.html](http://www.aerospike.com/docs/client/csharp/usage/logging.html) ---
**Author:** ![Brian](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.aerospike.com/brian/32/2211_2.png) [@Brian](https://discuss.aerospike.com/u/Brian)\ **Post date:** [May 16, 2017, 1:49am UTC](https://discuss.aerospike.com/t/aerospike-c-client-error-code-3/4160/3 "2017-05-16T01:49:47Z")
AerospikeException.InvalidNode is thrown in the following cases: 1. The client’s view of the cluster is empty (no nodes reachable). 2. The cluster tend thread can’t communicate a node. 3. AerospikeClient.scanNode() passes in a node name that doesn’t exist. I do recommend subscribing to the log because log messages are generated when nodes are added/dropped from the cluster and when nodes can’t be contacted. Set Log.Level to DEBUG to get all the messages. ---
**Author:** ![Igor](https://avatars.discourse-cdn.com/v4/letter/i/dec6dc/32.png) [@Igor](https://discuss.aerospike.com/u/Igor)\ **Post date:** [May 16, 2017, 3:50pm UTC](https://discuss.aerospike.com/t/aerospike-c-client-error-code-3/4160/4 "2017-05-16T15:50:43Z")
> [@Albot](#): > > I haven’t quite tied it back to a sync call volume though We have only one node, so it is not a real cluster. But after some debug our application, we understood that the problem was on application side. Error code -3 we got when tried to write a lot of entries at the same time with the same key. Why in our case we got Error -3, I dont know. Maybe debug level on aerospike server will help us understand. But I think we will try it some later. Thank you for help. ---
**Author:** ![Albot](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.aerospike.com/albot/32/2076_2.png) [@Albot](https://discuss.aerospike.com/u/Albot)\ **Post date:** [May 18, 2017, 1:52am UTC](https://discuss.aerospike.com/t/aerospike-c-client-error-code-3/4160/5 "2017-05-18T01:52:15Z")
Can you check to see if your queue was building during the time of Error Code -3? What you’re describing is a hotkey situation, in which case you should either see a hotkey exception or accumulation of requests transaction queue. [http://www.aerospike.com/docs/reference/serverlogmessages/](http://www.aerospike.com/docs/reference/serverlogmessages/) Depending on your server version, you need to look for a different message… Pre 3.9 - look for the number right after “q”: trans\_in\_progress: wr 23 prox 0 wait 0 ::: **q 1** ::: bq 0 ::: iq 0 ::: dq 0 : fds - proto (17, 2699692, 2699675) : hb (2, 3, 1) : fab (30, 44, 14) Post 3.9 - look for the number right after “tsvc-q” in-progress: **tsvc-q 0** info-q 5 nsup-delete-q 10 rw-hash 0 proxy-hash 0 tree-gc-q 0 ---
**Author:** ![Igor](https://avatars.discourse-cdn.com/v4/letter/i/dec6dc/32.png) [@Igor](https://discuss.aerospike.com/u/Igor)\ **Post date:** [May 19, 2017, 9:35am UTC](https://discuss.aerospike.com/t/aerospike-c-client-error-code-3/4160/6 "2017-05-19T09:35:51Z")
Hi. We tested again this error and we found the reason of our problem. Our App has a short-time operations with write data to aerospike. It realized with a lot of Threads Tasks in code. And in such short-time periods we had load on network about 200 Mbit/s. But size of network channel we had 100 Mbit/s. So in our case aerospike c# client returned Error code -3 because of overload network channel. Thanks all for help.