view flys-artifacts/src/main/java/de/intevation/flys/wsplgen/WSPLGENCallable.java @ 5779:ebec12def170

Datacage: Add a pool of builders to make it multi threadable. XML DOM is not thread safe. Therefore the old implementation only allowed one thread to use the builder at a time. As the complexity of the configuration has increased over time this has become a bottleneck of the whole application because it took quiet some time to build a result. Furthermore the builder code path is visited very frequent. So many concurrent requests were piled up resulting in long waits for the users. To mitigate this problem a round robin pool of builders is used now. Each of the pooled builders has an independent copy of the XML template and can be run in parallel. The number of builders is determined by the system property 'flys.datacage.pool.size'. It defaults to 4.
author Sascha L. Teichmann <teichmann@intevation.de>
date Sun, 21 Apr 2013 12:48:09 +0200
parents b87073a05f9d
children
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package de.intevation.flys.wsplgen;

import de.intevation.artifacts.CallContext;
import de.intevation.flys.artifacts.model.map.WSPLGENJob;

import java.io.File;
import java.io.IOException;
import java.util.concurrent.Callable;

import org.apache.log4j.Logger;


/**
 * A Callable that is used to start and observe an external Process for WSPLGEN.
 *
 * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
 */
public class WSPLGENCallable implements Callable {

    public static final String WSPLGEN_PARAMETER_FILE =
        "wsplgen.par";

    public static final String WSPLGEN_BIN_PATH =
        System.getProperty("wsplgen.bin.path");


    private Logger logger = Logger.getLogger(WSPLGENCallable.class);

    private Process process;

    protected Scheduler scheduler;

    protected WSPLGENJob job;

    protected JobObserver     logObserver;
    protected ProblemObserver errorObserver;


    public WSPLGENCallable(Scheduler scheduler, WSPLGENJob job) {
        this.scheduler     = scheduler;
        this.job           = job;
        this.logObserver   = new JobObserver(job);
        this.errorObserver = new ProblemObserver(job);
    }


    @Override
    public WSPLGENJob call() {
        File dir       = job.getWorkingDir();
        File parameter = new File(dir, WSPLGEN_PARAMETER_FILE);

        String[] args = new String[] {
            WSPLGEN_BIN_PATH,
            "-PAR=\"" + parameter.getAbsolutePath() + "\""
        };

        execute(args, dir);

        return job;
    }


    protected void execute(String[] args, File dir) {
        logger.info("Start JobExecutor for artifact: " + dir.getName());

        try {
            synchronized (this) {
                process = Runtime.getRuntime().exec(args, null, dir);

                logObserver.setInputStream(process.getInputStream());
                errorObserver.setInputStream(process.getErrorStream());

                logObserver.start();
                errorObserver.start();

                try {
                    process.waitFor();
                }
                catch (InterruptedException ie) {
                    logger.warn("WSPLGEN job interrupted: " + ie.getMessage());
                }

                try {
                    logObserver.join();
                    errorObserver.join();
                }
                catch (InterruptedException iee) { /* do nothing */ }

                logger.info("WSPLGEN exit value: " + process.exitValue());
                logger.info(
                    "WSPLGEN throw " +
                    errorObserver.numErrors() + " errors.");
                logger.info(
                    "WSPLGEN throw " +
                    errorObserver.numWarnings() + " warnings.");

                if (process.exitValue() < 2 && errorObserver.numErrors() == 0) {
                    FacetCreator fc = job.getFacetCreator();
                    fc.createWSPLGENFacet();
                    fc.finish();
                }

                job.getCallContext().afterBackground(CallContext.STORE);

                scheduler.removeJob(getJob().getArtifact().identifier());

                return;
            }
        }
        catch (SecurityException se) {
            logger.error(se);
        }
        catch (IOException ioe) {
            logger.error(ioe);
        }
        catch (NullPointerException npe) {
            logger.error(npe, npe);
        }
        catch (IndexOutOfBoundsException ioobe) {
            logger.error(ioobe, ioobe);
        }
    }


    public void cancelWSPLGEN() {
        if (process != null) {
            logger.debug("Cancel running WSPLGEN process.");
            process.destroy();
        }
    }


    public WSPLGENJob getJob() {
        return job;
    }
}
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