amazon dynamo db client in java- RejectedExecutionException

Question

I have an application that uses a dynamo db client, this seems to work fine most of the time but i am writing an integration test and getting this error, first it inserts fine and then the second time i go to insert i get this error.

Exception in thread "Thread-15" java.util.concurrent.RejectedExecutionException: Task java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask@6145f3ae rejected from java.util.concurrent.ScheduledThreadPoolExecutor@380892d7[Terminated, pool size = 0, active threads = 0, queued tasks = 0, completed tasks = 1]
    at java.util.concurrent.ThreadPoolExecutor$AbortPolicy.rejectedExecution(ThreadPoolExecutor.java:2063)
    at java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:830)
    at java.util.concurrent.ScheduledThreadPoolExecutor.delayedExecute(ScheduledThreadPoolExecutor.java:326)
    at java.util.concurrent.ScheduledThreadPoolExecutor.schedule(ScheduledThreadPoolExecutor.java:533)
    at com.amazonaws.http.timers.request.HttpRequestTimer.startTimer(HttpRequestTimer.java:61)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeOneRequest(AmazonHttpClient.java:1253)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeHelper(AmazonHttpClient.java:1072)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.doExecute(AmazonHttpClient.java:745)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeWithTimer(AmazonHttpClient.java:719)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.execute(AmazonHttpClient.java:701)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.access$500(AmazonHttpClient.java:669)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutionBuilderImpl.execute(AmazonHttpClient.java:651)
    at com.amazonaws.http.AmazonHttpClient.execute(AmazonHttpClient.java:515)
    at com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient.doInvoke(AmazonDynamoDBClient.java:3768)
    at com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient.invoke(AmazonDynamoDBClient.java:3737)
    at com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient.executePutItem(AmazonDynamoDBClient.java:2419)
    at com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient.putItem(AmazonDynamoDBClient.java:2387)
    at com.lmig.global.reuse.event.framework.attestation.Attestation.createEntry(Attestation.java:49)
    at com.lmig.global.reuse.event.framework.subscriber.Subscriber.process(Subscriber.java:86)
    at com.lmig.global.reuse.event.framework.subscriber.aws.AwsSubscriber.start(AwsSubscriber.java:88)
    at com.lmig.global.reuse.event.framework.subscriber.SubscriberFactory.lambda$loadAwsSubscribers$0(SubscriberFactory.java:64)
    at java.lang.Thread.run(Thread.java:748)

inserting like this

        amazonDynamoDB.putItem(itemRequest);

Thanks

Update - when add a try catch around and print the stack trace i get

Exception in thread "Thread-15" com.amazonaws.SdkClientException: Unable to execute HTTP request: The target server failed to respond
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.handleRetryableException(AmazonHttpClient.java:1134)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeHelper(AmazonHttpClient.java:1080)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.doExecute(AmazonHttpClient.java:745)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeWithTimer(AmazonHttpClient.java:719)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.execute(AmazonHttpClient.java:701)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.access$500(AmazonHttpClient.java:669)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutionBuilderImpl.execute(AmazonHttpClient.java:651)
    at com.amazonaws.http.AmazonHttpClient.execute(AmazonHttpClient.java:515)
    at com.amazonaws.services.sqs.AmazonSQSClient.doInvoke(AmazonSQSClient.java:2147)
    at com.amazonaws.services.sqs.AmazonSQSClient.invoke(AmazonSQSClient.java:2116)
    at com.amazonaws.services.sqs.AmazonSQSClient.invoke(AmazonSQSClient.java:2105)
    at com.amazonaws.services.sqs.AmazonSQSClient.executeReceiveMessage(AmazonSQSClient.java:1559)
    at com.amazonaws.services.sqs.AmazonSQSClient.receiveMessage(AmazonSQSClient.java:1530)
    at com.lmig.global.reuse.event.framework.subscriber.aws.AwsSubscriber.start(AwsSubscriber.java:70)
    at com.lmig.global.reuse.event.framework.subscriber.SubscriberFactory.lambda$loadAwsSubscribers$0(SubscriberFactory.java:64)
    at java.lang.Thread.run(Thread.java:748)
Caused by: org.apache.http.NoHttpResponseException: The target server failed to respond
    at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:141)
    at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:56)
    at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:259)
    at org.apache.http.impl.DefaultBHttpClientConnection.receiveResponseHeader(DefaultBHttpClientConnection.java:163)
    at org.apache.http.impl.conn.CPoolProxy.receiveResponseHeader(CPoolProxy.java:157)
    at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:273)
    at com.amazonaws.http.protocol.SdkHttpRequestExecutor.doReceiveResponse(SdkHttpRequestExecutor.java:82)
    at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:125)
    at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:272)
    at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:186)
    at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:185)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:83)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:56)
    at com.amazonaws.http.apache.client.impl.SdkHttpClient.execute(SdkHttpClient.java:72)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeOneRequest(AmazonHttpClient.java:1256)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeHelper(AmazonHttpClient.java:1072)
    ... 14 more
2020-05-25 16:50:10.462  INFO 5530 --- [      Thread-16] j.LocalContainerEntityManagerFactoryBean : Closing JPA EntityManagerFactory for persistence unit 'default'
2020-05-25 16:50:10.463  INFO 5530 --- [      Thread-16] .SchemaDropperImpl$DelayedDropActionImpl : HHH000477: Starting delayed evictData of schema as part of SessionFactory shut-down'
2020-05-25 16:50:10.471  INFO 5530 --- [      Thread-16] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Shutdown initiated...
2020-05-25 16:50:10.475  INFO 5530 --- [      Thread-16] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Shutdown completed.
Exception in thread "Thread-15" com.amazonaws.SdkClientException: Unable to execute HTTP request: The target server failed to respond
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.handleRetryableException(AmazonHttpClient.java:1134)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeHelper(AmazonHttpClient.java:1080)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.doExecute(AmazonHttpClient.java:745)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeWithTimer(AmazonHttpClient.java:719)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.execute(AmazonHttpClient.java:701)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.access$500(AmazonHttpClient.java:669)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutionBuilderImpl.execute(AmazonHttpClient.java:651)
    at com.amazonaws.http.AmazonHttpClient.execute(AmazonHttpClient.java:515)
    at com.amazonaws.services.sqs.AmazonSQSClient.doInvoke(AmazonSQSClient.java:2147)
    at com.amazonaws.services.sqs.AmazonSQSClient.invoke(AmazonSQSClient.java:2116)
    at com.amazonaws.services.sqs.AmazonSQSClient.invoke(AmazonSQSClient.java:2105)
    at com.amazonaws.services.sqs.AmazonSQSClient.executeReceiveMessage(AmazonSQSClient.java:1559)
    at com.amazonaws.services.sqs.AmazonSQSClient.receiveMessage(AmazonSQSClient.java:1530)
    at com.lmig.global.reuse.event.framework.subscriber.aws.AwsSubscriber.start(AwsSubscriber.java:70)
    at com.lmig.global.reuse.event.framework.subscriber.SubscriberFactory.lambda$loadAwsSubscribers$0(SubscriberFactory.java:64)
    at java.lang.Thread.run(Thread.java:748)
Caused by: org.apache.http.NoHttpResponseException: The target server failed to respond
    at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:141)
    at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:56)
    at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:259)
    at org.apache.http.impl.DefaultBHttpClientConnection.receiveResponseHeader(DefaultBHttpClientConnection.java:163)
    at org.apache.http.impl.conn.CPoolProxy.receiveResponseHeader(CPoolProxy.java:157)
    at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:273)
    at com.amazonaws.http.protocol.SdkHttpRequestExecutor.doReceiveResponse(SdkHttpRequestExecutor.java:82)
    at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:125)
    at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:272)
    at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:186)
    at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:185)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:83)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:56)
    at com.amazonaws.http.apache.client.impl.SdkHttpClient.execute(SdkHttpClient.java:72)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeOneRequest(AmazonHttpClient.java:1256)
    at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeHelper(AmazonHttpClient.java:1072)
    ... 14 more
2020-05-25 16:50:10.462  INFO 5530 --- [      Thread-16] j.LocalContainerEntityManagerFactoryBean : Closing JPA EntityManagerFactory for persistence unit 'default'
2020-05-25 16:50:10.463  INFO 5530 --- [      Thread-16] .SchemaDropperImpl$DelayedDropActionImpl : HHH000477: Starting delayed evictData of schema as part of SessionFactory shut-down'
2020-05-25 16:50:10.471  INFO 5530 --- [      Thread-16] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Shutdown initiated...
2020-05-25 16:50:10.475  INFO 5530 --- [      Thread-16] com.zaxxer.hikari.HikariDataSource       : HikariPool-1 - Shutdown completed.

Answer 1

below definition from AWS site:

Write capacity unit (WCU): Each API call to write data to your table is a write request. For items up to 1 KB in size, one WCU can perform one standard write request per second. Items larger than 1 KB require additional WCUs. Transactional write requests require two WCUs to perform one write per second for items up to 1 KB. For example, a standard write request of a 1 KB item would require one WCU, a standard write request of a 3 KB item would require three WCUs, and a transactional write request of a 3 KB item would require six WCUs.