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Lambda random long execution while running QLDB query

I have a lambda triggered by a SQS FIFO queue when there are messages on this queue. Basically this lambda is getting the message from the queue and connecting to QLDB through a VPC endpoint in order to run a simple SELECT query and a subsequent INSERT query. The table selected by the query has a index for the field used in the where condition. Flow (all the services are running "inside" a VPC): `SQS -> Lambda -> VPC interface endpoint -> QLDB` Query SELECT: `SELECT FIELD1, FIELD2 FROM TABLE1 WHERE FIELD3 = "ABCDE"` Query INSERT: `INSERT INTO TABLE1 .....` This lambda is using a shared connection/session on QLDB and this is how I'm connecting to it: ``` import { QldbDriver, RetryConfig } from 'amazon-qldb-driver-nodejs' let driverQldb: QldbDriver const ledgerName = 'MyLedger' export function connectQLDB(): QldbDriver { if ( !driverQldb ) { const retryLimit = 4 const retryConfig = new RetryConfig(retryLimit) const maxConcurrentTransactions = 1500 driverQldb = new QldbDriver(ledgerName, {}, maxConcurrentTransactions, retryConfig) } return driverQldb } ``` When I run a load test that simulates around 200 requests/messages per second to that lambda in a time interval of 15 minutes, I'm starting facing a random long execution for that lambda while running the queries on QLDB (mainly the SELECT query). Sometimes the same query retrieves data around 100ms and sometimes it takes more than 40 seconds which results in lambda timeouts. I have changed lambda timeout to 1 minute but this is not the best approch and sometimes it is not enough too. The VPC endpoint metrics are showing around 250 active connections and 1000 new connections during this load test execution. Is there any QLDB metric that could help to identify the root cause of this behavior? Could it be related to some QLDB limitation (like the 1500 active sessions described here: https://docs.aws.amazon.com/qldb/latest/developerguide/limits.html#limits.default) or something related to concurrency read/write iops?
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asked 5 days ago

Where to get started as a C/C++/C# developer?

Hello everyone, I've been a software and game developer for well over a decade, and I feel very at home with C, C++ and C#/.NET. I've done a lot of programming with DirectX SDKs and Unity, as well as desktop and mobile development. However, I don't really know much at all about the web and networking. But now I'm becoming very interested in what kinds of things I can do with AWS in game development, as well as with blockchain, AI/ML and cloud computing power. There seems to be more AWS services and packages than I can count though, and I'm really not sure which ones I should be pursuing and trying to learn more about and which ones are irrelevant to me and my job. The list of services, SDKs and packages is as impressive and inspiring as it is overwhelming and confusing! I'd like to be able to deploy some .NET applications to AWS to provide remote APIs for games and applications. To start with and get the hang of it, I just want to make a little minigame that lives on a server that a Unity or Unreal game can interact with through http requests. And I'll incrementally add some features to it as I start to get the hang of it. I'd also like to do some experimentation with blockchain software and services and see what kinds of interesting things can be accomplished with it. And beyond that, I'd eventually like to get into using AI/ML to accomplish goals in games and apps, harness cloud-based CPU/GPU processing power for heavy-lifting and even setup some real-time multiplayer game servers. I just don't know what tools/services/packages I need to dive into and start figuring out. I've found [the Visual Studio 2022 AWS package here](https://marketplace.visualstudio.com/items?itemName=AmazonWebServices.AWSToolkitforVisualStudio2022&ssr=false#overview), as well as [this AWS GitHub page](https://github.com/aws/dotnet) for .NET. I've also heard about Lambda. I really have no idea which ones are relevant to me or where I should start with this. To begin with, I want to run a .NET application on a server that applications can query and interact with and have it store and supply data for them, offer some remote APIs and requests, etc. I'd also potentially be interested in running some native C/C++ modules on servers. Can someone point me in the right direction and tell me what I need to set up and dive into first? I'm doing this in my free time when I'm not working on projects for work, so my time is very limited and researching and learning the wrong things would be a big setback for me. Any help or guidance is greatly appreciated!
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38
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asked 7 months ago

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