java.util.ConcurrentModificationException

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  • Got the following in a high-volume running crawl when requesting a web-UI frontier report. The error appeared in the browser, deep into the report (during the 'snoozed queues' listing). Ideally this shouldn't happen, even if the crawl is active. Or perhaps, if it is understandable, it should be captured and the report should note it and proceed as much as possible. ------- An error occured java.util.ConcurrentModificationException java.util.ConcurrentModificationException at java.util.TreeMap$PrivateEntryIterator.nextEntry(TreeMap.java:1031) at java.util.TreeMap$KeyIterator.next(TreeMap.java:1058) at org.archive.crawler.frontier.WorkQueueFrontier.appendQueueReports(WorkQueue Frontier.java:1235) at org.archive.crawler.frontier.WorkQueueFrontier.standardReportTo(WorkQueueFr ontier.java:1203) at org.archive.crawler.frontier.WorkQueueFrontier.reportTo(WorkQueueFrontier.j ava:1051) at org.archive.crawler.admin.CrawlJob.writeFrontierReport(CrawlJob.java:912) at org.archive.crawler.jspc.admin.reports.frontier_jsp._jspService(Unknown Source) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:137) at javax.servlet.http.HttpServlet.service(HttpServlet.java:853) at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:358) at org.mortbay.jetty.servlet.WebApplicationHandler$Chain.doFilter(WebApplicati onHandler.java:342) at org.archive.crawler.admin.ui.RootFilter.doFilter(RootFilter.java:67) at org.mortbay.jetty.servlet.WebApplicationHandler$Chain.doFilter(WebApplicati onHandler.java:334) at org.mortbay.jetty.servlet.WebApplicationHandler.dispatch(WebApplicationHand ler.java:286) at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:567) at org.mortbay.http.HttpContext.handle(HttpContext.java:1807) at org.mortbay.jetty.servlet.WebApplicationContext.handle(WebApplicationContex t.java:525) at org.mortbay.http.HttpContext.handle(HttpContext.java:1757) at org.mortbay.http.HttpServer.service(HttpServer.java:879) at org.mortbay.http.HttpConnection.service(HttpConnection.java:789) at org.mortbay.http.HttpConnection.handleNext(HttpConnection.java:960) at org.mortbay.http.HttpConnection.handle(HttpConnection.java:806) at org.mortbay.http.SocketListener.handleConnection(SocketListener.java:218) at org.mortbay.util.ThreadedServer.handle(ThreadedServer.java:300) at org.mortbay.util.ThreadPool$PoolThread.run(ThreadPool.java:511)
    via by Gordon Mohr,
  • Message from Igor: ==================== Hi Gordon, On crawling I get concurrent error during the UI frontier report. This only happens on the running crawl. I cannot reproduce it if the crawl is paused. ---------------------------- An error occured java.util.ConcurrentModificationException java.util.ConcurrentModificationException at java.util.TreeMap$PrivateEntryIterator.nextEntry(TreeMap.java:1031) at java.util.TreeMap$KeyIterator.next(TreeMap.java:1058) at org.archive.crawler.frontier.WorkQueueFrontier.appendQueueReports(WorkQueue Frontier.java:1235) at org.archive.crawler.frontier.WorkQueueFrontier.standardReportTo(WorkQueueFr ontier.java:1203) at org.archive.crawler.frontier.WorkQueueFrontier.reportTo(WorkQueueFrontier.j ava:1051) at org.archive.crawler.admin.CrawlJob.writeFrontierReport(CrawlJob.java:912) at org.archive.crawler.jspc.admin.reports.frontier_jsp._jspService(Unknown Source) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:137) at javax.servlet.http.HttpServlet.service(HttpServlet.java:853) at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:358) at org.mortbay.jetty.servlet.WebApplicationHandler$Chain.doFilter(WebApplicati onHandler.java:342) at org.archive.crawler.admin.ui.RootFilter.doFilter(RootFilter.java:67) at org.mortbay.jetty.servlet.WebApplicationHandler$Chain.doFilter(WebApplicati onHandler.java:334) at org.mortbay.jetty.servlet.WebApplicationHandler.dispatch(WebApplicationHand ler.java:286) at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:567) at org.mortbay.http.HttpContext.handle(HttpContext.java:1807) at org.mortbay.jetty.servlet.WebApplicationContext.handle(WebApplicationContex t.java:525) at org.mortbay.http.HttpContext.handle(HttpContext.java:1757) at org.mortbay.http.HttpServer.service(HttpServer.java:879) at org.mortbay.http.HttpConnection.service(HttpConnection.java:789) at org.mortbay.http.HttpConnection.handleNext(HttpConnection.java:960) at org.mortbay.http.HttpConnection.handle(HttpConnection.java:806) at org.mortbay.http.SocketListener.handleConnection(SocketListener.java:218) at org.mortbay.util.ThreadedServer.handle(ThreadedServer.java:300) at org.mortbay.util.ThreadPool$PoolThread.run(ThreadPool.java:511)
    via by (sourceforge),
  • exception when duplicating cell
    via by strubin,
  • Concurrent deploy failures?
    via GitHub by realityforge
    ,
    • java.util.ConcurrentModificationException at java.util.TreeMap$PrivateEntryIterator.nextEntry(TreeMap.java:1031) at java.util.TreeMap$KeyIterator.next(TreeMap.java:1058) at org.archive.crawler.frontier.WorkQueueFrontier.appendQueueReports(WorkQueueFrontier.java:1235) at org.archive.crawler.frontier.WorkQueueFrontier.standardReportTo(WorkQueueFrontier.java:1203) at org.archive.crawler.frontier.WorkQueueFrontier.reportTo(WorkQueueFrontier.java:1051) at org.archive.crawler.admin.CrawlJob.writeFrontierReport(CrawlJob.java:912) at org.archive.crawler.jspc.admin.reports.frontier_jsp._jspService(UnknownSource) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:137) at javax.servlet.http.HttpServlet.service(HttpServlet.java:853) at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:358) at org.mortbay.jetty.servlet.WebApplicationHandler$Chain.doFilter(WebApplicationHandler.java:342) at org.archive.crawler.admin.ui.RootFilter.doFilter(RootFilter.java:67) at org.mortbay.jetty.servlet.WebApplicationHandler$Chain.doFilter(WebApplicationHandler.java:334) at org.mortbay.jetty.servlet.WebApplicationHandler.dispatch(WebApplicationHandler.java:286) at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:567) at org.mortbay.http.HttpContext.handle(HttpContext.java:1807) at org.mortbay.jetty.servlet.WebApplicationContext.handle(WebApplicationContext.java:525) at org.mortbay.http.HttpContext.handle(HttpContext.java:1757) at org.mortbay.http.HttpServer.service(HttpServer.java:879) at org.mortbay.http.HttpConnection.service(HttpConnection.java:789) at org.mortbay.http.HttpConnection.handleNext(HttpConnection.java:960) at org.mortbay.http.HttpConnection.handle(HttpConnection.java:806) at org.mortbay.http.SocketListener.handleConnection(SocketListener.java:218) at org.mortbay.util.ThreadedServer.handle(ThreadedServer.java:300) at org.mortbay.util.ThreadPool$PoolThread.run(ThreadPool.java:511)

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