Question

I'm trying to set up a glassfish 4.0 cluster with 2 instances using Apache 2.2 with mod_jk for load balancing. Everything is working as expected, except for a servlet used to serve images.

When I access this servlet on an instance I get the image content without problems (see image below).

(Unfortunaely I was not able to post the image because of my low reputation)

But when I access this servlet through load balance I get garbage data on the content (see image below).

(Again, I couldn't post the image, but basically the top part of the image is ok, but from the middle to the bottom image parts get mixed and with colors anomaly)

I have noticed that this problem doesn't happen with small images - up to 10KB - just with images larger than that.

I have also noticed that another servlet that serves text content is having a similiar problem, but in that case, the servlet send just part of the file and the request takes nonsenses 1.5 minutes for a 32.6 KB response (!?!?!?)

Here is the part of the servlet code responsible for serving the image content:

try{
    // Open streams.
    input = new BufferedInputStream(new FileInputStream(fimage),
    DEFAULT_BUFFER_SIZE);
    output = new BufferedOutputStream(response.getOutputStream(),
        DEFAULT_BUFFER_SIZE);

    // Write file contents to response.
    byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
    int length;
    while ((length = input.read(buffer)) > 0) {
        output.write(buffer, 0, length);
    }

    output.flush();
    }

    } catch (Exception e) {
        // Tratamento de erros
    logger.log(Level.SEVERE, "Falha ao servir imagem", e);
    try {
        response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
    return;
    } catch (IOException ex) {
        logger.log(Level.SEVERE, "Falha ao responder erro", ex);
    }
} finally {
    // Close stream
        if (input != null)
        try {
        input.close();
        } catch (IOException e) {
        logger.log(Level.SEVERE, "Falha ao fechar input", e);
        }
    }

Here are entries on httpd.conf

LoadModule jk_module modules/mod_jk.so

JkWorkersFile conf/workers.properties
JkLogFile logs/mod_jk.log
JkLogLevel debug
JkLogStampFormat "[%a %b %d %H:%M:%S %Y] "
JkOptions +ForwardKeySize +ForwardURICompat -ForwardDirectories
JkRequestLogFormat "%w %V %T"

#HTTPS Configuration
JkExtractSSL On
JkHTTPSIndicator HTTPS
JkSESSIONIndicator SSL_SESSION_ID
JkCIPHERIndicator SSL_CIPHER
JkCERTSIndicator SSL_CLIENT_CERT

JkMount /olhameubebe/* loadbalancer

Listen 443
<VirtualHost _default_:443> 
    ServerAdmin some@email.com 
    DocumentRoot "Your Root folder location" 
    ServerName www.domain.com:443 
    ServerAlias domain.com:443 
    ErrorLog "logs/anyFile-error.log" 
    CustomLog "logs/anyFile-access.log" common 
    SSLEngine on
    SSLCertificateFile "C:/Program Files (x86)/Apache Software Foundation/Apache2.2/bin/server.crt"
    SSLCertificateKeyFile "C:/Program Files (x86)/Apache Software Foundation/Apache2.2/bin/server.key" 
    JkMount /olhameubebe/* loadbalancer
</VirtualHost>

The worker.properties file looks like

# Define 1 real worker using ajp13
worker.list=worder1,worker2,loadbalancer

# Set properties for worker1 (ajp13)
worker.worker1.type=ajp13
worker.worker1.host=localhost
worker.worker1.port=28080
worker.worker1.socket_keepalive=0

# Set properties for worker2 (ajp13)
worker.worker2.type=ajp13
worker.worker2.host=localhost
worker.worker2.port=28081
worker.worker2.socket_keepalive=0

# Set properties for loadbalancer
worker.loadbalancer.type=lb
worker.loadbalancer.balance_workers=worker1,worker2
worker.loadbalancer.sticky_session=1

I'm doing this test on windows and I don't see any error/warning on log files.

Does anybody have any idea about what Am I doing wrong?

Thanks in advance!

Does anyone have any idea about what is going wrong?

*EDIT:

After a lot of attemps and experiments, looks like the problem was solved after I remove "Content-Length" from response headers.

So I just had to comment this line from servlet's code:

//response.setHeader("Content-Length", String.valueOf(fimage.length()));
Was it helpful?

Solution

After a lot of attemps and experiments, looks like the problem was solved after I remove "Content-Length" from response headers.

So I just had to comment this line from servlet's code:

//response.setHeader("Content-Length", String.valueOf(fimage.length()));
Licensed under: CC-BY-SA with attribution
Not affiliated with StackOverflow
scroll top