High GC object churn with many threads in org.apache.cxf.endpoint.ClientImpl

Issue

• JBoss is performing poorly and GC occurs very frequently. It frees plenty of space, but the old generation fills rapidly again to cause Full GCs again. Thread dumps during this time show many threads in org.apache.cxf.endpoint.ClientImpl, appending strings and copying arrays:

"JSFqueue-threads - 239" prio=10 tid=0x00007f4608524000 nid=0x5cca runnable [0x00007f45b3fb6000]
   java.lang.Thread.State: RUNNABLE
    at java.util.Arrays.copyOf(Arrays.java:2882)
    at java.lang.AbstractStringBuilder.expandCapacity(AbstractStringBuilder.java:100)
    at java.lang.AbstractStringBuilder.append(AbstractStringBuilder.java:390)
    at java.lang.StringBuilder.append(StringBuilder.java:119)
    at java.util.Arrays.toString(Arrays.java:4071)
    at java.util.concurrent.CopyOnWriteArrayList.toString(CopyOnWriteArrayList.java:860)
    at java.lang.String.valueOf(String.java:2826)
    at java.lang.StringBuilder.append(StringBuilder.java:115)
    at org.apache.cxf.endpoint.ClientImpl.onMessage(ClientImpl.java:731)
...
"JSFqueue-threads - 234" prio=10 tid=0x00007f460851d000 nid=0x5c07 runnable [0x00007f45b41b7000]
   java.lang.Thread.State: RUNNABLE
    at java.lang.AbstractStringBuilder.<init>(AbstractStringBuilder.java:45)
    at java.lang.StringBuilder.<init>(StringBuilder.java:68)
    at java.lang.Object.toString(Object.java:219)
    at java.lang.String.valueOf(String.java:2826)
    at java.util.Arrays.toString(Arrays.java:4071)
    at java.util.concurrent.CopyOnWriteArrayList.toString(CopyOnWriteArrayList.java:860)
    at java.lang.String.valueOf(String.java:2826)
    at java.lang.StringBuilder.append(StringBuilder.java:115)
    at org.apache.cxf.endpoint.ClientImpl.setupInterceptorChain(ClientImpl.java:946)