Nginx做负载均衡报:nginx: [emerg] could not build the types_hash

环境：KVM/Centos6.3

用Nginx做负载均衡的时候在配置完成后，启动Nginx的时候报：

nginx: [emerg] could not build the types_hash, you should increase either types_hash_max_size: 1024 or types_hash_bucket_size: 32

解决方法：在nginx配置文件http模块添加:types_hash_max_size 2048;

http{
    include       mime.types;
    default_type application/octet-stream;
    types_hash_max_size 2048;
    server_names_hash_bucket_size 128;
    client_header_buffer_size 32k;
    large_client_header_buffers 4 32k;

错误原因真心不知道，只能Google了，方法找到了，错误原因也找到了，但真心不明白什么意思。

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I found out nginx is reporting the wrong cache line size on a virtual system.

On startup it reports:

Restarting nginx: nginx: [emerg] could not build the types_hash, you should
increase either types_hash_max_size: 1024 or types_hash_bucket_size: 32

This is caused by /etc/nginx/mime.types having a key which is 36 bytes long:

echo -n application/vnd.google-earth.kml+xml |wc -c
36

In src/core/ngx_cpuinfo.c , the ngx_cpuinfo() reports my CPU has having a 32 bytes cache line which is then used as the default value for types_hash_bucket_size and thus trigger the startup error.