[TIKA-2939] Figure out how to allow OCR'ing of large PDFs via tika-server

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Component/s: server
• Assignee: Unassigned
• Reporter: Tim Allison
• Created: 09/Sep/19 10:35
• Updated: 23/Oct/20 21:23

Description

Tesseract can take quite a bit of time on large PDFs, which can lead to timeouts in jax-rs and the connection closing:

Caused by: com.ctc.wstx.exc.WstxIOException: Closed
        at com.ctc.wstx.sw.BaseStreamWriter.flush(BaseStreamWriter.java:262)
        at org.apache.cxf.jaxrs.interceptor.JAXRSDefaultFaultOutInterceptor.handleMessage(JAXRSDefaultFaultOutInterceptor.java:104)
Caused by: org.eclipse.jetty.io.EofException: Closed
        at org.eclipse.jetty.server.HttpOutput.write(HttpOutput.java:491)
        at org.apache.cxf.transport.http_jetty.JettyHTTPDestination$JettyOutputStream.write(JettyHTTPDestination.java:322)
        at org.apache.cxf.io.AbstractWrappedOutputStream.write(AbstractWrappedOutputStream.java:51)
        at com.ctc.wstx.sw.EncodingXmlWriter.flushBuffer(EncodingXmlWriter.java:742)
        at com.ctc.wstx.sw.EncodingXmlWriter.flush(EncodingXmlWriter.java:176)
        at com.ctc.wstx.sw.BaseStreamWriter.flush(BaseStreamWriter.java:260)

I tried expanding the timeouts on the client side:

 RequestConfig config = RequestConfig.custom()
                .setConnectTimeout(TIMEOUT * 1000)
                .setConnectionRequestTimeout(TIMEOUT * 1000)
                .setSocketTimeout(TIMEOUT * 1000).build();

But this doesn't solve the problem.

How can we/can we increase the timeout on the server side and is there a maximum?

If we can't fix the problem with timeouts, we should figure out a way to let people select only a few pages for OCR so that clients can iterate through large PDFs.

This issue is different from TIKA-1871 in that the problem isn't chunking the large document to get the file to tika-server; rather the problem is the amount of time it can take tika-server to run OCR on every page of a large PDF and return the full results.