isochrone-api

API to serve and calculate isochrones

Isochrone calculation stages:

• Spanning tree generation (time_annotated_spanning_tree_v5.sql):
  • Define starting point as the nearest osm node
  • Define possible area as 2 hours walk/drive time from starting point
  • Calculate driving distance(time) for each road segment
• Resulted spanning tree is returned to FrontEnd in WKB format in order to speed up calculation process for a user
• Calculate point isochrone based on spanning tree. Split isochrone into 5min sections. (calculate_isochrones_dumppoints_v5.sql)
• Calculate isochrone for the whole user input (which might be more than one point) (closest_voronoi_v3.sql)

Startup process

To start Jetty Server run app without any options. After server is run it restarts processing for uncalculated isochrones.

Due to MyBatis integration -h option requires DB connection and either should be run with --config=<yaml_location> or environment variables with db connection should be set.

Example: java -jar isochrone-api-1.0-SNAPSHOT.jar --config=<yaml_location> -h

Here is list of available options and env variables:

OPTIONS

  --calculation-restart
       Restarts isochrone calculation.

  --catalog=catalog_name
       Catalog against which 'liquibase dropAll' will be executed.

  --config=yaml_location
       Specifies YAML config location, which can be a file path or a URL.

  -h, --help
       Prints this message.

  -H, --help-config
       Prints information about application modules and their configuration
       options.

  --lb-changelog-sync
       Mark all changes as executed in the database.

  --lb-changelog-sync-sql
       Writes SQL to mark all changes as executed in the database to STDOUT.

  --lb-clear-check-sums
       Clears all checksums in the current changelog, so they will be
       recalculated next update.

  -x [val], --lb-context[=val]
       Specifies Liquibase context to control which changeSets will be
       executed in migration run.

  -d [val], --lb-default-schema[=val]
       Specifies the default schema to use for managed database objects and
       for Liquibase control tables.

  --lb-drop-all
       Drops all database objects in the configured schema(s). Note that
       functions, procedures and packages are not dropped.

  -u, --lb-update
       Updates DB with available migrations

  -v, --lb-validate
       Checks the changelog for errors.

  -s schema_name, --schema=schema_name
       Schema against which 'liquibase dropAll' will be executed.

ENVIRONMENT

  DB_MAX_POOL_SIZE

  DB_PASSWORD

  DB_URL

  DB_USER

Postgis & etc

PostGIS should be installed with --with-sfcgal option
Install pgRouting: https://docs.pgrouting.org/3.1/en/pgRouting-installation.html

Other dependencies

http extension for postgresql:
https://github.com/pramsey/pgsql-http.git

Run on your database before running with "-u" option:

CREATE EXTENSION postgis;
CREATE EXTENSION postgis_sfcgal;
CREATE EXTENSION uuid-ossp;
CREATE EXTENSION btree_gist;
CREATE EXTENSION pgRouting;
CREATE EXTENSION http;

install functions from https://github.com/mapbox/postgis-vt-util