[NUTCH-2579] Fetcher to use parsed URL to call ProtocolFactory.getProtocol(url)

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Implemented
• Affects Version/s: 1.14
• Fix Version/s: 1.15
• Component/s: fetcher, protocol
• Assignee: Sebastian Nagel
• Reporter: Sebastian Nagel
• Created: 18/May/18 16:16
• Updated: 01/Oct/19 14:29
• Resolved: 13/Jun/18 08:20

Description

The call of ProtocolFactory.getProtocol(url) is synchronized and causes waits for the lock in a multi-threaded fetcher. It uses the URL string, although it would be more efficient to use the parsed URL hold in the FetchItem. The lock could be released faster. In addition, parsing the URL also causes a lock in the URL stream handler:

"FetcherThread" #37 daemon prio=5 os_prio=0 tid=0x00007f21edea2000 nid=0x5c20 waiting for monitor entry [0x00007f21bacb4000]
   java.lang.Thread.State: BLOCKED (on object monitor)
        at java.util.Hashtable.get(Hashtable.java:363)
        - waiting to lock <0x00000005e01b5840> (a java.util.Hashtable)
        at java.net.URL.getURLStreamHandler(URL.java:1135)
        at java.net.URL.<init>(URL.java:599)
        at java.net.URL.<init>(URL.java:490)
        at java.net.URL.<init>(URL.java:439)
        at org.apache.nutch.protocol.ProtocolFactory.getProtocol(ProtocolFactory.java:74)
        - locked <0x00000005fc5f4fb8> (a org.apache.nutch.protocol.ProtocolFactory)
        at org.apache.nutch.fetcher.FetcherThread.run(FetcherThread.java:299)

Issue Links

• links to: GitHub Pull Request #334