Mike Scott's questions

I have a MySQL instance containing a number of databases, one of which is an archive database (although using the INNODB rather than ARCHIVE storage engine) that is not queried or written to in normal operation.

The data filesystem is filling up and I'd like to move the archive database's data directory to a different filesystem (and then symlink it back, obviously). If there are no SQL statements attempting to query or update the data during the move, can I safely do this while the MySQL instance and the other databases stay online and in use?

I plan to rsync the database directory to the new filesystem, then rename the old one on the original filesystem to something different and create the new symlink. lsof reports that MySQL does have the .ibd files open, so presumably it would have to reopen them.

I'm trying to use an Apache proxy as a front-end for a service running on a different server in my infrastructure. Let's call them proxy.example.com and service.example.com.

Proxy.example.com is listening on port 80, but service.example.com is listening on port 8888. The first thing that service.example.com does when you connect to it is to send a 302 redirect which has port 8888 included in it -- and Apache is correctly remapping the domain name but not the port in the redirect. The service on service.example.com is a third-party packaged product, so let's assume that we can't change the way it works in any way.

The relevant bit of Apache config looks like this:

ProxyPreserveHost On
ProxyPass / http://service.example.com:8888/
ProxyPassReverse / http://service.example.com:8888/

Here are some (lightly anonymised) telnets to port 80. First, going direct to service.example.com:

$ telnet service.example.com 8888
Trying xxx.xxx.xxx.xxx...
Connected to service.example.com.
Escape character is '^]'.
GET / HTTP/1.0
Host: service.example.com

HTTP/1.0 302 Found
Date: Thu, 19 Jan 2012 10:38:54 GMT
Content-Type: text/html
Location: http://service.example.com:8888/directory/index.html

Connection closed by foreign host.

And going via proxy.example.com:

$ telnet proxy.example.com 80
Trying yyy.yyy.yyy.yyy... 
Connected to proxy.example.com.
Escape character is '^]'.
GET / HTTP/1.0
Host: proxy.example.com

HTTP/1.1 302 Found
Date: Thu, 19 Jan 2012 10:41:08 GMT
Location: http://proxy.example.com:8888/directory/index.html
Via: 1.0 service.example.com
Vary: Accept-Encoding
Content-Length: 0
Connection: close

Connection closed by foreign host.

So, how can I make Apache remap the port number as well as the domain name in the 302 redirect?

I'm running an nginx instance that's acting as an SSL termination point and basic load balancer on an EC2 virtual server, and seeing very poor performance for the SSL pages served from the upstream source.

The EC2 instance is a c1.medium, and ought to be able to sustain a reasonable throughput, but I can't get it above 60 transactions per second.

Serving the nginx status page directly off the server, I manage more than ten times the throughput, so it's not purely SSL overhead, but if I reconfigure it to serve the same content without SSL I also do very much better, so it's also not upstream overhead. The CPU is maxed out while it's serving its 60 transactions per second.

I'm using ab to test it, with parameters "-n 1000 -c 50 -k" -- 1000 hits, concurrency of 50, keepalives enabled so that the SSL session caching ought to work.

Here's an abbreviated config:

user www-data;
worker_processes 4;
pid /var/run/nginx.pid;

events {
    worker_connections 4096;
}

http {
    sendfile off;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 65;
    types_hash_max_size 2048;

    include /etc/nginx/mime.types;
    default_type application/json;

    log_format standard '$remote_addr - $remote_user [$time_local] "$request" $status $body_bytes_sent "$http_referer" "$http_user_agent"';

    access_log /var/log/nginx/access.log standard;
    error_log /var/log/nginx/error.log;

    gzip on;
    gzip_types text/plain application/json;
    gzip_comp_level 1;

    upstream test {
    server 10.226.31.66;
    }

server {
    listen   443;

    ssl on;
    ssl_certificate     /etc/nginx/certs/both.crt;
    ssl_certificate_key /etc/nginx/certs/https.key;

    ssl_session_timeout  10m;
    ssl_session_cache   shared:SSL:10m;

    ssl_protocols  SSLv2 SSLv3 TLSv1;
    ssl_ciphers  ALL:!kEDH:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP;
    ssl_prefer_server_ciphers   on;

    location /v1/system/nginx {
        stub_status on;
        allow all;
    }

    location /nginx_status {
        stub_status on;
        allow all;
    }

    location / {

        proxy_pass      http://test;
        proxy_set_header   Host $host;
        proxy_set_header   X-Forwarded-For  $proxy_add_x_forwarded_for;

        client_max_body_size   10m;
        client_body_buffer_size 128k;

        proxy_buffering on;
        proxy_connect_timeout 15;
        proxy_intercept_errors on;
    }
    }
    }