Excel extactor causes OOME on studio

Thread 25511: (state = BLOCKED)
 - java.util.Arrays.copyOf(char[], int) @bci=1, line=2882 (Compiled frame)
 - java.lang.AbstractStringBuilder.expandCapacity(int) @bci=33, line=100 (Compiled frame)
 - java.lang.AbstractStringBuilder.append(java.lang.String) @bci=36, line=390 (Compiled frame)
 - java.lang.StringBuilder.append(java.lang.String) @bci=2, line=119 (Compiled frame)
 - com.atlassian.confluence.extra.officeconnector.index.excel.ExcelXMLTextExtractor.extractText(java.io.InputStream, com.atlassian.bonnie.search.SearchableAttachment) @bci=169, line=71 (Compiled frame)
 - com.atlassian.bonnie.search.extractor.BaseAttachmentContentExtractor.addFields(org.apache.lucene.document.Document, java.lang.StringBuffer, com.atlassian.bonnie.Searchable) @bci=142, line=40 (Interpreted frame)
 - com.atlassian.confluence.plugin.descriptor.ExtractorModuleDescriptor$BackwardsCompatibleExtractor.addFields(org.apache.lucene.document.Document, java.lang.StringBuffer, com.atlassian.bonnie.Searchable) @bci=7, line=45 (Interpreted frame)
 - com.atlassian.bonnie.search.BaseDocumentBuilder.getDocument(com.atlassian.bonnie.Searchable) @bci=52, line=104 (Interpreted frame)
 - com.atlassian.confluence.search.lucene.ConfluenceDocumentBuilder.getDocument(com.atlassian.bonnie.Searchable) @bci=5, line=102 (Interpreted frame)
 - com.atlassian.confluence.search.lucene.tasks.AddDocumentIndexTask.perform(org.apache.lucene.index.IndexWriter) @bci=9, line=43 (Interpreted frame)
 - com.atlassian.confluence.search.lucene.tasks.UpdateDocumentIndexTask.perform(org.apache.lucene.index.IndexWriter) @bci=32, line=40 (Interpreted frame)
 - com.atlassian.confluence.search.lucene.tasks.BulkWriteIndexTask.perform(org.apache.lucene.index.IndexWriter) @bci=31, line=44 (Interpreted frame)
 - com.atlassian.bonnie.LuceneConnection.withWriter(com.atlassian.bonnie.ILuceneConnection$WriterAction) @bci=41, line=331 (Interpreted frame)
 - com.atlassian.confluence.search.lucene.tasks.LuceneConnectionBackedIndexTaskPerformer.perform(com.atlassian.confluence.search.lucene.tasks.ConfluenceIndexTask) @bci=5, line=20 (Interpreted frame)
 - com.atlassian.confluence.search.lucene.DefaultConfluenceIndexManager$BatchUpdateAction.perform() @bci=132, line=361 (Interpreted frame)
 - com.atlassian.bonnie.LuceneConnection.withBatchUpdate(com.atlassian.bonnie.ILuceneConnection$BatchUpdateAction) @bci=22, line=405 (Interpreted frame)
 - com.atlassian.confluence.search.lucene.DefaultConfluenceIndexManager.processTasks(java.util.List, com.atlassian.confluence.search.lucene.FlushStatistics) @bci=52, line=161 (Interpreted frame)
 - com.atlassian.confluence.search.lucene.DefaultConfluenceIndexManager.flushQueue(boolean) @bci=205, line=128 (Interpreted frame)
 - sun.reflect.GeneratedMethodAccessor656.invoke(java.lang.Object, java.lang.Object[]) @bci=63 (Interpreted frame)
 - sun.reflect.DelegatingMethodAccessorImpl.invoke(java.lang.Object, java.lang.Object[]) @bci=6, line=25 (Compiled frame)
 - java.lang.reflect.Method.invoke(java.lang.Object, java.lang.Object[]) @bci=161, line=597 (Compiled frame)
 - org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(java.lang.Object, java.lang.reflect.Method, java.lang.Object[]) @bci=31, line=304 (Compiled frame)
 - org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint() @bci=12, line=182 (Compiled frame)
 - org.springframework.aop.framework.ReflectiveMethodInvocation.proceed() @bci=19, line=149 (Compiled frame)
 - org.springframework.transaction.interceptor.TransactionInterceptor.invoke(org.aopalliance.intercept.MethodInvocation) @bci=79, line=106 (Compiled frame)
 - org.springframework.aop.framework.ReflectiveMethodInvocation.proceed() @bci=101, line=171 (Compiled frame)
 - org.springframework.aop.framework.JdkDynamicAopProxy.invoke(java.lang.Object, java.lang.reflect.Method, java.lang.Object[]) @bci=359, line=204 (Compiled frame)
 - $Proxy40.flushQueue(boolean) @bci=19 (Interpreted frame)
 - com.atlassian.confluence.search.lucene.IndexQueueFlusher.executeJob(org.quartz.JobExecutionContext) @bci=55, line=29 (Interpreted frame)
 - com.atlassian.confluence.setup.quartz.AbstractClusterAwareQuartzJobBean.surroundJobExecutionWithLogging(org.quartz.JobExecutionContext) @bci=47, line=63 (Interpreted frame)
 - com.atlassian.confluence.setup.quartz.AbstractClusterAwareQuartzJobBean.executeInternal(org.quartz.JobExecutionContext) @bci=168, line=46 (Interpreted frame)
 - org.springframework.scheduling.quartz.QuartzJobBean.execute(org.quartz.JobExecutionContext) @bci=63, line=86 (Compiled frame)
 - org.quartz.core.JobRunShell.run() @bci=241, line=199 (Compiled frame)
 - com.atlassian.confluence.schedule.quartz.ConfluenceQuartzThreadPool$1.run() @bci=7, line=14 (Compiled frame)
 - org.quartz.simpl.SimpleThreadPool$WorkerThread.run() @bci=82, line=549 (Compiled frame)