README
¶
dp-graph
A library to abstract graph database logic away from services
Configuration
| Environment variable | Default | Description |
|---|---|---|
| GRAPH_DRIVER_TYPE | "" | string identifier for the implementation to be used (e.g. 'neo4j' or 'mock') |
| GRAPH_ADDR | "" | address of the database matching the chosen driver type |
| GRAPH_POOL_SIZE | 0 | desired size of the connection pool |
| MAX_RETRIES | 0 | maximum number of attempts for transient query failures |
| RETRY_TIME | 20ms for Neptune | the initial sleep time between requests in the retry package |
| GRAPH_QUERY_TIMEOUT | 0 | maximum number of seconds to allow a query before timing out |
All config other than GRAPH_DRIVER_TYPE will be subject to that implementation to make use of
and set reasonable defaults for use in that context. It's feasible that some implementations
might not have configurable timeouts for example, so whether this can be set should be
documented in each driver.
Neptune specific configuration
| Environment variable | Default | Description |
|---|---|---|
| NEPTUNE_BATCH_SIZE_READER | 25000 | batch size for queries to a reader endpoint |
| NEPTUNE_BATCH_SIZE_WRITER | 150 | batch size for queries to a writer endpoint |
| NEPTUNE_MAX_WORKERS | 150 | maximum number of workers in the Neptune pool |
| NEPTUNE_TLS_SKIP_VERIFY | false | flag to skip TLS certificate verification, should only be true when run locally |
Design
See DESIGN for details.
Health package
The Graph checker function is currently implemented only for Neo4J. It connects to Neo4J and performs a 'ping query', just to validate that we can communicate with it. The health check will succeed only if the query succeeds.
Read the Health Check Specification for details.
Instantiate a Neo4J client
cli := neo4jdriver.New(<dbAddr>, <size>, <timeout>)
Call Neo4J health checker with cli.Checker(context.Background()) and this will return a check object:
{
"name": "string",
"status": "string",
"message": "string",
"status_code": "int",
"last_checked": "ISO8601 - UTC date time",
"last_success": "ISO8601 - UTC date time",
"last_failure": "ISO8601 - UTC date time"
}
Contributing
See CONTRIBUTING for details.
License
Copyright © 2019, Office for National Statistics (https://www.ons.gov.uk)
Released under MIT license, see LICENSE for details.
Directories
¶
| Path | Synopsis |
|---|---|
|
This module, when combined with codelist.go, provides code that satisfies the graph.driver.CodeList interface using Gremlin queries into a Neptune database.
|
This module, when combined with codelist.go, provides code that satisfies the graph.driver.CodeList interface using Gremlin queries into a Neptune database. |