On 10/27/2016 4:58 AM, Linkezhang wrote: > > *Problem:* > > In the client using some method (such as telnet) to establish a tcp > connection with server-side apache listening port , but after the > establishment of tcp connection, the client does not send any data. > However, apache will not disconnect this tcp connection, may lead to > the number of connections exhausted , Resulting in DOS > > *The attack process**：** > *1. The client executes the telnet service port > > Start the client telnet server port 60000, do not exit for a long time:
I tried this with version 6.2.0, telnetting to port 8983. I find that the telnet disconnects after a short time. The Jetty config that's in an unmodified Solr install has a 50 second idle timeout, which is likely what is causing the disconnect. It's likely possible to change the Jetty config so that Solr would behave this way, but I see no evidence of a problem in the default Solr config. Your subject mentions "PHP" ... but Solr doesn't use PHP. There are several PHP clients for Solr, but they are developed by third parties. The Lucene/Solr project is not involved with their development at all. Solr defaults to port 8983, but you are connecting to port 60000. Did you change the port number, or have you installed something between the user and Solr? If it's the embedded zookeeper port you are connecting to (which defaults to port 9983, not 60000), Solr's use of zookeeper is almost entirely unmodified. The embedded zookeeper server does currently have code inside Solr that parses the configuration, rather than leaving that part up to zookeeper itself, but the zookeeper server (and all its networking) is not a part of Solr's code. I also tried telnetting to the embedded zookeeper server that Solr (also version 6.2.0) is capable of starting (on port 9983). It took a little longer than Solr itself, about four minutes, but it did eventually disconnect when there was no activity. The latest version of Solr is 6.2.1, which is nearly identical to 6.2.0, except for a few minor bugfixes, none of which would involve networking code. All of the networking code for Solr is actually provided by other projects -- Jetty and Zookeeper. Thanks, Shawn --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org
