I put this at the end of my main handler:
Aws postgresql lambda 2018 code#
The best solution I’ve found to overcome the context.callbackWaitsForEmptyEventLoop = false issue when running tests locally is to conditionally execute code if I’m in the test environment. This will allow you to freeze the connection while still having control over when it connects. I’m not sure what you’re using for a database connection, but you should instantiate your Class outside of your handler, and then create a connect() method that gets triggered inside your handler. To answer your Stack Overflow question, try this post I wrote about stubbing AWS services: The Lambda documentation tells you to keep your variable declarations inside your handler function. Lambda does handle setting up DB connections really well under heavy load, but I still favor connection reuse as it cuts several milliseconds off your execution time. Cold starts still average greater than 100ms.
Aws postgresql lambda 2018 update#
Update : After running some new tests, it appears that “warm” functions now average anywhere between 4 and 20ms to connect to RDS instances in the same VPC. Luckily, Lambda lets us “freeze” and then “thaw” these types of connections. Add that to your queries and whatever additional processing you need to perform and it becomes unusable under normal circumstance. If we have to reconnect to the database every time we run our Lambda functions (especially if we’re responding to an API request) then we are already adding over 200ms to the total response time. In my experience it typically takes more than 200ms. Setting up a new database connection is relatively expensive. However, since Lambda is stateless, you’ll most likely need to query a persistent datastore in order for it to do anything exciting. There’s no longer the need to run several underutilized processing servers just waiting for someone to request a large job.ĪWS Lambda is event-driven, so it’s also possible to have it respond to API requests through AWS’s API Gateway. FaaS is great for a number of use cases (like processing images) because it will scale immediately and near infinitely when there are spikes in traffic. This is what’s known as a “ Serverless” architecture since we do not need to provision any servers in order to run these functions. The ability to use this Functions-as-a-Service (FaaS) has dramatically reduced the complexity and hardware needs of the apps I work on.
Update : I wrote an NPM module that manages MySQL connections for you in serverless environments.