Java running out of memory on VPS

Question

The program has no apparent memory leaks and while I am observing it run the locally in my machine it works fine. On the VPS it crashes after few hours with a sequence of error messages as shown below.

Exception in thread "Thread-10422" java.lang.OutOfMemoryError: Java heap space

I don't understand why such an error would occur after hours instead of few minutes if there is a memory leak. I used tools such as VisualVM to observe the behavior of the program and the memory runs constant throughout.

Is anyone aware of any ways I can debug this and get to the bottom of this or how to avoid it?

Is there a tool that requires no installation and can observe the memory usage of a process over ssh?

Edit: There is no stack trace on all the exceptions which is weird. But the error happens in different threads for different classes.

at java.io.BufferedWriter.<init>(BufferedWriter.java:104)
at java.io.BufferedWriter.<init>(BufferedWriter.java:87)
at java.io.PrintStream.init(PrintStream.java:100)
at java.io.PrintStream.<init>(PrintStream.java:142)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:411)
at sun.net.www.http.HttpClient$2.run(HttpClient.java:457)
at java.security.AccessController.doPrivileged(Native Method)
at sun.net.www.http.HttpClient.privilegedOpenServer(HttpClient.java:454)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:521)
at sun.net.www.http.HttpClient.<init>(HttpClient.java:240)
at sun.net.www.http.HttpClient.New(HttpClient.java:321)
at sun.net.www.http.HttpClient.New(HttpClient.java:338)
at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:935)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:914)
at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:801)


at java.util.HashMap.resize(HashMap.java:479)
at java.util.LinkedHashMap.addEntry(LinkedHashMap.java:431)
at java.util.HashMap.put(HashMap.java:402)
at org.jsoup.nodes.Attributes.put(Attributes.java:58)
at org.jsoup.parser.Token$Tag.newAttribute(Token.java:65)
at org.jsoup.parser.TokeniserState$34.read(TokeniserState.java:791)
at org.jsoup.parser.Tokeniser.read(Tokeniser.java:42)
at org.jsoup.parser.TreeBuilder.runParser(TreeBuilder.java:47)
at org.jsoup.parser.TreeBuilder.parse(TreeBuilder.java:41)
at org.jsoup.parser.HtmlTreeBuilder.parse(HtmlTreeBuilder.java:37)
at org.jsoup.parser.Parser.parseInput(Parser.java:30)
at org.jsoup.helper.DataUtil.parseByteData(DataUtil.java:102)
at org.jsoup.helper.HttpConnection$Response.parse(HttpConnection.java:498)
at org.jsoup.helper.HttpConnection.get(HttpConnection.java:154)

EDIT: After setting maximum memory I am getting this error

OpenJDK 64-Bit Server VM warning: Attempt to allocate stack guard pages failed.

Answer 1

This clearly indicates that you are running out of the heap space. So you can try by increasing the heap space of the Java virtual machine using coomand java -Xms<initial heap size> -Xmx<maximum heap size>

As per my knowledge, default values are initial: 32M and maximum: 128M. So can make it max value as 256M or 512M.

Have a look at this for information about the Java VM. http://www.oracle.com/technetwork/java/javase/tech/vmoptions-jsp-140102.html