[DIRMINA-764] DDOS possible in only a few seconds...

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Won't Fix
• Affects Version/s: 2.0.0-RC1
• Fix Version/s: 2.0.8
• Assignee: Emmanuel Lécharny
• Reporter: Emmanuel Lécharny
• Created: 15/Feb/10 13:45
• Updated: 10/Sep/14 21:15
• Resolved: 10/Sep/14 21:15

Description

We can kill a server in just a few seconds using the stress test found in DIRMINA-762.

If we inject messages with no delay, using 50 threads to do that, the ProtocolCodecFilter$MessageWriteRequest is stuffed with hundred of thousands messages waiting to be written back to the client, with no success.

On the client side, we receive almost no messages :
0 messages/sec (total messages received 1)
2 messages/sec (total messages received 11)
8 messages/sec (total messages received 55)
8 messages/sec (total messages received 95)
9 messages/sec (total messages received 144)
3 messages/sec (total messages received 162)
1 messages/sec (total messages received 169)
...

On the server side, the memory is totally swamped in 20 seconds, with no way to recover :
Exception in thread "pool-1-thread-1" java.lang.OutOfMemoryError: Java heap space

(see graph attached)

On the server, ConcurrentLinkedQueue contain the messages to be written (in my case, 724 499 Node are present). There are also 361629 DefaultWriteRequests, 361628 DefaultWriteFutures, 361625 SimpleBuffer, 361 618 ProtocolCodecFilter$MessageWriteRequest and 361 614 ProtocolCodecFilter$EncodedWriteRequests.

That mean we don't flush them to the client at all.

Issue Links

• is related to: DIRMINA-762 WARN org.apache.mina.core.service.IoProcessor - Create a new selector. Selected is 0, delta = 0