Beaconizer

Beaconizer is a different build of mapserver, which loads maps and generates .bcn files.

Operating modes

Beaconizer has to be started in one of the following modes:

• BeaconClient
• Master-BeaconServer
• Auto-BeaconServer
• Manual-BeaconServer
• Request-BeaconServer

Selecting one of these modes causes the mapserver to start as a beaconizer, and alters normal mapserver startup in the following ways:

• d_ prefixes in data files would normally cause the file to be ignored by mapserver; beaconizer does not do this
• Popup error dialogs are suppressed
• FolderCache is set to filesystem-only mode, so piggs will not be read
• Shared memory is disabled
• Server command processing is not done
• Animations are not loaded
• Container management and the usual dbserver client do not start
• The beaconizer client or server is started, according to the mode

Beaconizer can run in development or production mode. This is unrelated to all other forms of development or production mode in mapserver, and controlled exclusively by the -beaconproductionmode flag.

BeaconServer listens on the first free port in the range port 48812 (0xbeac) to 48913, except for Master-BeaconServer which listens on 48813, and no other BeaconServer will listen on that port. All beaconservers accept the same network commands.

Launcher has special handling for launching Master-BeaconServer, BeaconClients, and Request-BeaconServer instances.

Beaconizer will install itself as c:/beaconizer/BeaconServer.exe and c:/beaconizer/BeaconClient.exe. It will copy these executables to c:/beaconizer/beaconcopy.XX.XX.(YYYY-mm-dd).(HH-MM-SS)/BeaconServer.exe as it runs, and relaunch processes from those paths.

Master server

The Master-BeaconServer starts two worker threads.

The file loader waits for load requests to arrive, reads the corresponding .beaconrequest file from the cache dir (checking that the file version and crc match), then marks the load request as complete.

The request processor queues all requests in the ${cache_dir}/pending on startup, then scans the process queue for work it can do. On each pass it will:

• Take up to three nodes in state WAITING_FOR_WRITE_TO_DISK and write their map data packet to ${cache_dir}/pending/${name}.pending
• For the first 50Mb of compressed map data in the queue, load the map data from the pending file if it is in state WAITING_FOR_MAP_DATA_FROM_DISK and move it to state WAITING_FOR_REQUEST_SERVER. For the rest of the map data in the queue, free it and park it in state WAITING_FOR_MAP_DATA_FROM_DISK. This caps the amount of data held in memory at 50Mb.

In production mode, the master server will connect to dbserver and send BEACON2DB_BEACONSERVER_STATUS messages roughly once a second, with the longest outstanding client request wait time.

In its main processing loop, the master server:

• processes all clients to assign them work and check pings
  • any connected client of type BCT_SERVER which is a Request server and does not currently have a process node assigned, will select the first process node in the queue in state WAITING_FOR_REQUEST_SERVER and assign it to this server. This sends BMSG_S2CT_MAP_DATA to that server.
• scans the process queue for completed work
  • any nodes without a requester are cancelled
  • any process node in state WAITING_FOR_LOAD_REQUEST which has completed loading (by the file loader thread) is checked for load success. If the file was loaded, then it is sent to the client and the state moves to WAITING_FOR_CLIENT_TO_RECEIVE_BEACON_FILE. Otherwise, it moves to state WAITING_TO_REQUEST_MAP_DATA_FROM_CLIENT
  • any process node in state WAITING_TO_REQUEST_MAP_DATA_FROM_CLIENT is checked to see if all map data has been received, and moved to state WAITING_FOR_WRITE_TO_DISK. If not all map data has been received, then the first five process nodes in this state will send BMSG_S2CT_REQUEST_CHUNK_RECEIVED to the client and move to state WAITING_FOR_MAP_DATA_FROM_CLIENT
  • process nodes in state WAITING_FOR_MAP_DATA_FROM_CLIENT count towards the five node limit if the request was sent less than three seconds ago
• assigns available clients to servers which need them

This gives us the following state machine for process nodes:

• Created in state WAITING_FOR_LOAD_REQUEST in response to BMSG_C2ST_REQUESTER_MAP_DATA
• File loader thread attempts to load the data
• If valid data is found, moves to state WAITING_FOR_CLIENT_TO_RECEIVE_BEACON_FILE. This is a terminal state; it stays here until the client is done.
• If no valid data is found, the main processing loop advances it to WAITING_TO_REQUEST_MAP_DATA_FROM_CLIENT
• When the master server has capacity to continue (5 at a time), it sends BMSG_S2CT_REQUEST_CHUNK_RECEIVED to the client and moves to state WAITING_FOR_MAP_DATA_FROM_CLIENT
• When a chunk of map data is received, moves to WAITING_TO_REQUEST_MAP_DATA_FROM_CLIENT (loop back up)
• When all map data is received, moves to WAITING_FOR_WRITE_TO_DISK
• When the processing thread has capacity (3 at a time), writes the map data to a pending file
• If too much data is pending, unloads some so that only 50Mb of map data is held in memory waiting for request servers, and queues it for reloading when there is capacity (state WAITING_FOR_MAP_DATA_FROM_DISK)
• When capacity is available, moves to WAITING_FOR_REQUEST_SERVER
• When a Request server is available, assigns the work to that server and sends BMSG_S2CT_MAP_DATA
• When the request server sends BMSG_C2ST_BEACON_FILE, moves the state to WAITING_FOR_CLIENT_TO_RECEIVE_BEACON_FILE and begins sending the file

Command-line flags

-beaconclient <master name>	Start as BeaconClient. Set the master server name.
-beaconserver <master name>	Start as Manual-BeaconServer. Set the master server name.
-beaconautoserver <master name>	Start as Auto-BeaconServer. Set the master server name.
-beaconmasterserver	Start as Master-BeaconServer.
-beaconrequestserver <master name>	Start as Request-BeaconServer. Set the master server name.
-beaconclientsubserver <subserver name>	Set the subserver name for this client.
-beaconusemasterserver <master address>	Set the network address to connect to the master server.
-beaconrequestcachedir <cache dir>	Set the request cache directory. Default is c:/beaconizer/requestcache
-beaconproductionmode	Set the beaconizer into production mode. If this flag is not used then it will be in development mode.
-beaconallownovodex
-beaconsymstore	Only used on a master server. Runs symstoreVS8.exe to add BeaconServer.exe, BeaconClient.exe, BeaconServer.pdb and BeaconClient.pdb to a symstore.
-beaconworkduringuseractivity
-beaconnonetstart
-beaconnoperforce
-beacondatatoolsrootpath <path>	Set the data/tools root path.