LoopBack 4 data source mixin to handle database operation retries in case of Azure Cosmos DB request limit errors caused by exceeding the available Request Units.
Some dependencies need to be installed as peer dependencies
@loopback/repositorynpm install loopback4-cosmosdb-retryThe mixin just needs to added to the data source
import { juggler } from "@loopback/repository";
import { RetryMixin } from "loopback4-cosmosdb-retry";
class CosmosdbDataSource extends RetryMixin(juggler.DataSource) {}The default values can be directly overwritten in the data source class
class CosmosdbDataSource extends RetryMixin(juggler.DataSource) {
constructor(args) {
super(args);
// do 19 retries after the first request (default: 9)
this.maxRetries = 19;
// default delay if no suggested delay is in error response (default: 1000)
this.retryAfterInMs = 2000;
// additional delay to add to the suggested delay in error response (default: 0)
this.retryAfterPaddingInMs = 200;
// always use fixed retry interval based on retryAfterInMs (default: false)
this.useFixedRetryInterval = false;
}
}or by using environment variables
.env
MAX_RETRIES=19
RETRY_AFTER_IN_MS=2000
RETRY_AFTER_PADDING_IN_MS=200
USE_FIXED_RETRY_INTERVAL=falseNote: The values you are setting directly in your code will have precedence over the environment variables. If you want to be able to set values in your code while also having the options to overwrite with environment variables you need to manually handle this.
// ...
constructor(args) {
super(args);
this.maxRetries = Number(process.env.MAX_RETRIES) ?? 19;
}
// ...To enable debug logs set the DEBUG environment variable to loopback:cosmosdb-retry, see
Setting debug strings for further details.
This project is licensed under the MIT license. See the LICENSE file for more info.