Multi-Server Load Balancing

To spread a database across multiple servers the database must first be appropriately chunked. A ShapeDatabaseServer.py is started on each host with its corresponding database chunk. ShapeDatabaseProxy.py is then used to tie all the servers together to appear like a single shape database service to client applications. Theoretically, there is no need for the client to know whether it is querying one or many servers.

The general work-flow is as follows:

1. Split up database into 2 servers:

   ShapeDatabaseChunker.py database.oeb.gz database_shapedb.oeb.gz 2
   

2. Start a shape database server on each host:

   # host1
   ShapeDatabaseServer.py database_shapedb_1.oeb.gz
   
   # host2:
   ShapeDatabaseServer.py database_shapedb_2.oeb.gz
   

3. Start a proxy server to point to all the hosts. Note, a different port number like 8081 may need to be specified if the proxy server is being started on a host that already has a ShapeDatabaseServer.py started on it.:

   # proxy
   ShapeDatabaseProxy.py host1:8080 host2:8080 8081
   

4. Query the proxy server:

   ShapeDatabaseClient.py proxy:8081 query.sdf overlays.oeb