Processing data in GeoServer with WPS and SQL views

Processing Data In GeoServer With WPS And SQL Views

Ing. Andrea Aime, GeoSolutions

Ing. Alessio Fabiani, GeoSolutions

FOSS4G-Europe 2014, Bremen 14th-17th July 2014

FOSS4G Europe 2014, Bremen 14th-17th July 2014

Some historical perspective

Year 2008:

Publish maps on the net

Nice styling, maybe time/elevation based selector, some little extra filtering

Maybe some editing, some PDF printing

Year 2013:

All of the above, but…

We can hardly make a new application without some data processing in it

WPS: some quick reminders


Web Processing Service

Wikipedia introduces OGC WPS as:

[A service] designed to standardize the way that GIS calculations are made available to the Internet.

WPS can describe any calculation including all of its inputs and outputs, and trigger its execution

The specific processes served up by a WPS implementation are defined by the owner of that implementation.

Although WPS was designed to work with spatially referenced data, it can be used with any kind of data.


An Example

Buffer a L shaped geometry with distance “2”

Get the result back as GML


GeoServer WPS integration

WPS

Remote WCS

Remote WFS

HTTP server

WPS client

All GeoServer Layers

WMS client WMS

GeoServer UI


Rendering transformations

On-the-fly data transformations inside rendering

chain

Calling WPS processes from SLD docs

Optimized for performance


• GeoServer ships with lots of built-in processes

• Basic geometry manipulation

• Aggregation options missing from WFS

• Raster and vector clipping

• And more!

• Ability to chain processes to build more complex functionality

• Open API to manage inputs and outputs

• See all of it at http://demo.geo-solutions.it/share/foss4g2011/wps_aaime_foss4g2011.pdf

More On GeoServer WPS

http://demo.geo-solutions.it/share/foss4g2011/wps_aaime_foss4g2011.pdf





When the WPS does not cut it…


• Never under-estimate the processing power of your BDMS:

• Designed to efficiently juggle large quantities of data

• Efficient spatial primitives (at least, in PostGIS)

• Doesn’t get more local to your data than this!

• Passing params down?

• Parametric SQL views!

Spatial DBMS!


Parametric SQL views

WMS/WFS client

GeoServer

Spatial database

&viewparams=low:2000000;high:5000000

Expanded Query

Enough theory Let’s get down to business!

FAO Tuna Atlas


Mapping Tuna Catches

• Multiple Filtering

• Aggregation

• Joining quartely stats against the grid


Filtering, joining and aggregation

Some example control regexps: • Y_INTERV:

• Default: 1

• Regex: ^(\d)+$

• OP

• Default: sum

• Regex: ^[avg|sum]$

SELECT (T.TS_VALUE / %Y_INTERV%) AS TS_VALUE, T.CD_TA_OCEANAREA, G.GEOMETRY FROM (SELECT CD_TA_OCEANAREA, OP%(TS_VALUE) AS TS_VALUE FROM FIGIS.TS_FI_TA WHERE FIC_ITEM IN (%FIC_ITEM%) AND CD_GEAR IN (%CD_GEAR%) AND YR_TA IN (%YR_TA%) AND QTR_TA IN (%QTR_TA%) GROUP BY CD_TA_OCEANAREA ) t LEFT OUTER JOIN FIGIS_GIS.GRID_G5 g ON T.CD_TA_OCEANAREA = g.CD_OAREA ORDER BY T.CD_TA_OCEANAREA


• Animator tool

• GetMap + variying parameters + frame control => animated GIF!

• http://docs.geoserver.org/stable/en/user/tutorials/animreflector.html

Animation


• …/geoserver/wms/animate?request=GetMap&… &format=image/gif;subtype=animated &aparam=viewparams:YR_TA &avalues=2000,2001,2002,2003,…

Animator

What’s the wheater like today?


The Situation

• MetOc data is extremely dynamic

• In-Situ sensors acquire data in near real-time

• Meteorological and Oceanographic model runs multiple times a day

• Remote Sensing data is acquired at fast pace

• Meteo Radar data is acquired at fast pace

• Large amount of data is produced to model fast changing environmental variables

• We must shorten to the small possible extent the time and resources for preprocessing!


Solutions: On-the-fly contouring


Solutions: On-the-fly Wind-Barbs


Solutions: On-the-fly Currents


Solutions: On-the-fly Storm Tracks

Download services


• New addition to the MapStore project

• Requirements

• Download large amounts of data

• Generic data filtering

• Clip on polygon/bbox/circle, both vector and raster

• Reproject to target CRS

• Mail notification when download is ready (or fails)

• Work in a cluster

• Solution: new WPS processes, asynch WPS calls and WPS customization for state sharing

Advanced Clip and Ship

http://mapstore.geo-solutions.it/mapstore/

http://mapstore.geo-solutions.it/mapstore/


MapStore GUI

Buffer process called synchronously when buffer size changes


MapStore GUI

Tracking download status (asynch WPS)


Download service architecture

WPS

All GeoServer Layers

Ma

pS

tore

WMS

GetCapabilities List of layers

Buffer

DownloadEstimator

Download

GetStatus

Fetch data

Status database

Store and retrieve status

Mail server

Custom process manager

Start/ Complete/

Failed

notifications

The CMRE-IDA Project


• The Integrated Decision Aid (IDA) has been developed at the Centre for Maritime Research and Experimentation (CMRE) in order to provide naval exercise planners with an effective tool to assess risk to marine mammals from acoustic transmissions.

• Assessment of potential hazard is performed through sound propagation modeling available in the interface.

Intro

Sound Propagation Model



• External Octave Matlab Process

• Logs the asynchronous process status to the DB as a Feature

Octave Matlab Script for SPM

WFS Follows the process status through the WFS WFSLog

Process allows to insert and update the status of SPM into the DB

Dynamically builds an external Octave command line using the input parameters through a FreeMarker Template (FTL)


• The list of model runs is available on the bottom Data Grid.

• It is possible to get information on the input parameters and execution from the WFS



• Advanced Raster Algebra using Jiffle

• Wraps Jiffle (http://code.google.com/p/jiffle/) in order to execute complex Raster Algebra scripts against the input layers

Raster Algebra Processes

Jiffle is a scripting language for creating and analysing raster images. Rather than having to write and test lots of JAI or Java AWT boiler-plate code to access and manipulate images, Jiffle lets you concentrate on the interesting bit: your algorithm. Jiffle is being developed as part of the JAITools project. Update 16 January 2013: Jiffle sources have moved to GitHub

http://code.google.com/p/jiffle/

http://code.google.com/p/jiffle/

http://jaitools.org/



http://jai-tools.blogspot.com.au/2013/01/jaitools-and-jiffle-go-to-github.html

http://jai-tools.blogspot.com.au/2013/01/jaitools-and-jiffle-go-to-github.html


• Advanced Raster Algebra using Jiffle

• Gets an OGC Filter containing logical operations between raster layers and produces a binary light layer



• Raster Algebra detailed info

• Input parameters and outcomes are logged into WFS

• WPS Raster Stats Process provides statistics on the coverages


Raster Statistics and Area in sq Km

Raster Algebra Process user inputs

Script me plenty An example using GeoScript


Sample scripting application

http://localhost:8080/geoserver/www/wps.html


Land property distrib. in the polygon


A look at the data dir

1. Data

2. WPS process scripted in Jython

3. The GUI


The Jython script

http://geoscript.org/py/index.html

The Destination Project


• The Destination project computes the risk of accidents involving dangerous goods (chemicals, petrol, gases and so on)

Intro

Road segments and stats about car accidents

Human and environmental «targets»

Involved area, depending on type of good and amount of damage


• Road network of good part of northern Italy

• Road divided into segments

• 100m portions (500k of them)

• 500m aggregation (120k of them)

• 1 km square cells (few hundreds)

• 51 buffer distances (depending on good, scenario, level of damage)

• Several types of targets: schools, malls, hospitals, populated areas, superficial and underground acquifers, crops, woods, ….

Large Data Volume


The road arc risk formula (s)

• Adding togheter the risk caused by the different

• Arc own propension to accidentds

• Types of goods

• Human and enviromental targets

• The system allows to compute partial views of the formula, either by selection of targets/goods or by computing portions of it

• Has a number of coefficients that can be hand-tuned by the caller


The results, visually

• Rendering transformation

• Read the arcs/polys from the DB, compute their risk based on the chosen formula, scenario, targets, and coefficients


How to compute it efficiently?

• Using SQL Views? No, the possible aggregations variants are too many

• Using a pure Java process? No, too much data to transfer from the DBMS

• Fully on the fly? No, too much data involved

• Pre-compute all buffers and locate all involved targets before hand (pre-cooked per buffer risk)

• Use a process that builds a final aggregation query on the fly (dynamic sql views)


Efficient rendering tx

Risk process

Queries database

Arcs/Buffer areas db

Map renderer

Build overall query, replace params

Compute risk for a batch of arcs

Raw arcs

Arcs + risk

• Compute risk on the fly in the viewing area

• Batch requests to the BDMS to minimize round-trip overhead


Efficient cross layer filtering

• Show only targets involved in the scenario under study, e.g., the ones crossing the buffer areas where there is significant risk

• Limit query to the current bbox


Efficient cross layer filtering

SELECT v_geo_popolazione_residente_pl.*

FROM v_geo_popolazione_residente_pl

WHERE v_geo_popolazione_residente_pl.fk_bersaglio_umano_pl in

(

SELECT distinct bersaglio.fk_bersaglio_umano_pl

FROM v_geo_popolazione_residente_pl bersaglio

join siig_geo_ln_arco_1 on

st_dwithin(bersaglio.geometria,

siig_geo_ln_arco_1.geometria,

%distanzaumano%) WHERE siig_geo_ln_arco_1.geometria &&

st_makeenvelope(%bounds%, 32632) )

• This is a job for a parametric sql view


The End

Questions? [email protected]

[email protected]

Processing data in GeoServer with WPS and SQL views

Technology

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