调试易

有台服务器ContOS+nginx+mysql。运行截图如下Tasks: 254 total,   1 running, 253 sleeping,   0 stopped,   0 zombie
Cpu(s):  2.3%us,  0.3%sy,  0.0%ni, 96.6%id,  0.8%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:   8150256k total,  8081236k used,    69020k free,   564908k buffers现在的问题是，总体上流畅，只在进行搜索时变慢，多个搜索并发时比较卡。搜索语句已进行过优化，请高手帮忙优化mysql
my.cnf如下：[client]
port = 3306
socket = /tmp/mysql.sock[mysqld]
port = 3306
socket = /tmp/mysql.sock
skip-locking
net_buffer_length = 8K
sql-mode=""
connect_timeout=15
interactive_timeout=100
join_buffer_size=1M
key_buffer=256M
max_allowed_packet=16M
max_connections=4000
max_connect_errors=10
myisam_sort_buffer_size=64M
read_buffer_size=1M
read_rnd_buffer_size=768K
sort_buffer_size=8M
table_cache=1024
thread_cache_size=100
thread_concurrency=8
wait_timeout=100
query_cache_size=64M
query_cache_limit=1M
query_cache_type=1
tmp_table_size = 400M
#max_heap_table_size = 64Mlong_query_time = 5
log-slow-queries = /home/slow.log
log-queries-not-using-indexesskip-name-resolvelog-bin=mysql-binserver-id = 1
[mysqldump]
quick
max_allowed_packet = 16M[mysql]
no-auto-rehash[isamchk]
key_buffer = 20M
sort_buffer_size = 20M
read_buffer = 2M
write_buffer = 2M[myisamchk]
key_buffer = 20M
sort_buffer_size = 20M
read_buffer = 2M
write_buffer = 2M[mysqlhotcopy]
interactive-timeout