Occasional ArrayIndexOutOfBoundsException due to SimpleDateFormat use

[mdeeks]

We're heavily using jolokia in our environment for monitoring purposes. Occasionally jolokia dies and returns 500s with the exception pasted below. I'm guessing it is due to the re-use of SimpleDateFormat in JolokiaHttpHandler. From the Javadocs: "Date formats are not synchronized. It is recommended to create separate format instances for each thread. If multiple threads access a format concurrently, it must be synchronized externally."

Once jolokia gets into this state it does not recover without restarting the process. Here is the exception I get when doing a GET /jolokia/version on one of the broken instances:

java.lang.ArrayIndexOutOfBoundsException: -2147483648
    at java.util.Calendar.getDisplayName(Calendar.java:2098)
    at java.text.SimpleDateFormat.subFormat(SimpleDateFormat.java:1125)
    at java.text.SimpleDateFormat.format(SimpleDateFormat.java:966)
    at java.text.SimpleDateFormat.format(SimpleDateFormat.java:936)
    at java.text.DateFormat.format(DateFormat.java:345)
    at org.jolokia.jvmagent.JolokiaHttpHandler.setHeaders(JolokiaHttpHandler.java:225)
    at org.jolokia.jvmagent.JolokiaHttpHandler.handle(JolokiaHttpHandler.java:139)
    at com.sun.net.httpserver.Filter.doFilter(Filter.java:79)
    at sun.net.httpserver.AuthFilter.doFilter(AuthFilter.java:83)
    at com.sun.net.httpserver.Filter.doFilter(Filter.java:82)
    at sun.net.httpserver.ServerImpl.handle(ServerImpl.java:675)
    at com.sun.net.httpserver.Filter.doFilter(Filter.java:79)
    at sun.net.httpserver.ServerImpl.run(ServerImpl.java:647)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

[rhuss]

Thanks for the report, I will have a look at it. Probably on friday (sorry, busy right now ...)

[markus-meisterernst]

Hi Roland,

da ich die Sourcen gerade offen hatte ...:

Das SimpleDateFormat ist nicht ThreadSafe. Daher sollte es nicht als Instanzvariable gecached werden (sofern der Zugriff nicht synchronisiert ist).

daher, statt
headers.set("Date",rfc1123Format.format(cal.getTime()));
besser durch:
headers.set("Date",new SimpleDateFormat().format(cal.getTime()));
ersetzen.

Hope that helps.

Grüße,

Markus

Am 03.03.2015 um 14:42 schrieb Roland Huß notifications@github.com:

Thanks for the report, I will have a look at it. Probably on friday (sorry, busy right now ...)

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