GSKY: Distributed Scalable Geospatial Data Server

What Is This?

GSKY was developed at NCI and is a scalable, distributed server which presents a new approach for geospatial data discovery and delivery using OGC standards. The most recent release is version 1.0 (June 2018).

License

Copyright 2016, 2017, 2018 Australian National University

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this package except in compliance with the License. A copy of the License may be found in this source distribution in LICENSE-2.0.txt.

Contributions

Suggestions, enhancement requests, bug reports and patches to GSKY are welcome via this GitHub page. Please submit patches as a GitHub pull request. Authors retain copyright over their contributions.

Citing GSKY in publications

When referring to GSKY in publications please use the citation in CITATION.md. A ready-to-use BibTeX entry for LaTeX users can also be found in this file.

Configuration Files

1. config.json: Contains the list of WMS, WCS and WPS layers exposed by the server. It also contains the IP address of the index API used in the workflow. In addtion, it contains the list of worker nodes specifying the IP address and list of ports per worker. Several workers can be specified on a single machine by adding several entries using the same IP address and different ports. These services have to be locally started at the specified machines.

2. Serveral config.json files can be organized into directories to form namespaces to group logical collection of datasets together. For example, the server serves two science projects with the following URLs:

   1) http://<server address>/ows/project1
   2) http://<server address>/ows/project2
   

   The directory structure of the config files will be as follows:

   <config root directory>
   
       project1
          config.json
   
       project2
          config.json
   

How To Compile the Source

Dependencies:

• Go > 1.6.0
• GDAL > 2.1.0
• Various Go packages (handled by the build system)

$ export GOPATH=~/go
$ go get github.com/nci/gsky
$ cd $GOPATH/src/github.com/nci/gsky
$ ./configure
$ make all install

The configure script takes all of the standard GNU configure flags such as --prefix (to specify where to install GSKY).

Overview of the Servers

GSKY mainly consists of three servers working together to deliver services. The main server (ows.go) is the front-end server that takes WMS/WCS/WPS HTTP requests as inputs. The main server talks to the MAS Restful API server (mas/api/api.go) for the data files that intersect with the polygon bounding box in the WMS/WCS/WPS requests. With those data files, the main server talks to the RPC worker nodes (grpc-server/main.go) for compute and IO intensive tasks and then sends the results back to the client side.

How To Start the Servers

• Start the MAS Restful API server: /opt/gsky/sbin/masapi -port 8888

  The -port option sets the API server listening port. The default is port 8080.

• Start all the RPC worker nodes: /opt/gsky/sbin/gsky-rpc -p 6000

  The -p option sets the gRPC listening port. The default is port 6000.

• Start the main server: /opt/gsky/sbin/gsky-ows -p 8080

  The -p option sets the main server listening port. The default is port 8080.