[hadoop@dtydb6 logs]$ ulimit -a
core file size (blocks, -c) 0
data seg size (kbytes, -d) unlimited
scheduling priority (-e) 0
file size (blocks, -f) unlimited
pending signals (-i) 1064960
max locked memory (kbytes, -l) 32
max memory size (kbytes, -m) unlimited
open files (-n) 1024
pipe size (512 bytes, -p) 8
POSIX message queues (bytes, -q) 819200
real-time priority (-r) 0
stack size (kbytes, -s) 10240
cpu time (seconds, -t) unlimited
max user processes (-u) 1064960
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimited
而查看flume进程打开的文件数量为2932（这个比较奇怪，怎么超过1024了呢？）
12988 Jps
26903 JobTracker
29828 Application
26545 DataNode
27100 TaskTracker
26719 SecondaryNameNode
26374 NameNode
[root@dtydb6 ~]# lsof -p 29828|wc -l
2932
[root@dtydb6 ~]# ps -ef|grep 29828
root 13133 12914 0 14:05 pts/3 00:00:00 grep 29828
hadoop 29828 1 32 Jan22 ? 8-10:51:15 /usr/java/jdk1.7.0_07/bin/java -Xmx2048m -cp /monitor/flume-1.3/conf:/monitor/flume-1.3/lib/*:/hadoop/hadoop-1.0.4/libexec/../conf:/usr/java/jdk1.7.0_07/lib/tools.jar:/hadoop/hadoop-1.0.4/libexec/..:/hadoop/hadoop-1.0.4/libexec/../hadoop-core-1.0.4.jar:/hadoop/hadoop-1.0.4/libexec/
解决方案：
1.修改nfile配置文件，手工增加nofile的大小
vi /etc/security/limits.conf
* soft nofile 12580
* hard nofile 65536
2.重启flume进程，也就是进程29828，问题解决