问题
Good morning, Could you please help us with next problem: I have an API Gateway + Java Lambda Handler. this Lambda uses httpconnection to get some Internet REST API.
when we use this Lambda without VPC it works fine. but when we are using VPC with configured internet access - sometimes Lambda fails with timeout errors. it fails in 20% of all requests (80% requests works fine) with next errors at log.
REPORT RequestId: 16214561-b09a-11e6-a762-7546f12e61bd Duration: 15000.26 ms Billed Duration: 15000 ms Memory Size: 512 MB Max Memory Used: 47 MB
09:57:49
2016-11-22T09:57:49.245Z 16214561-b09a-11e6-a762-7546f12e61bd Task timed out after 15.00 seconds
According to my logs lambda cannot send GET request. I'm not sure where the problem at. Is this Lambda issue, VPC issue or some cofiguration issue. Also I did try many different REST Api endpoints, so it's definetly not an endpoint issue.
Appreciate any help.
回答1:
When you place a Lambda function inside your VPC it will not have access to anything outside the VPC. To enable your Lambda function to access resources outside the VPC you have to add a NAT Gateway to your VPC.
回答2:
The problem is solved.
Lambda VPC configuration had public subnet attached.
Thanks to @Michael-sqlbot
回答3:
I had pretty much the same issue a few months ago, and here is my solution:
Assuming you set up your Lambda manually, in the Configuration -> Advanced settings you will find the VPC and then choose subnet and security groups.
The Subnet you selected should be in the same subnet with other services the lambda function invokes. In your case, your lambda service uses httpconnection to Internet rest API, that's fine, but you may need DB connection with RDS or triggered by SQS or SNS. So make sure the subnet is correct.
The Security Groups is more important. Again, in your case, you need the access to Internet, so ensure the security group's outbound rules has external connections. Normally, I give all ports and all destination available for simplicity, and of course, you can limit to use port 80 and the API's IP address you need.
回答4:
From your log,
- Billed Duration: 15000 ms
- Memory Size: 512 MB
- Max Memory Used: 47 MB
Solution:
It is timeout issue. You need to increase the execution time 15 seconds to 30 seconds or more if necessary.
In some cases, you also need to increase the memory size. It may also make effect. But I think time is the main fact for you, not memory size.
For timing issue and testing issue, you can go through the followings:
Q: How long can an AWS Lambda function execute?
Soluiton: All calls made to AWS Lambda must complete execution within 300 seconds. The default timeout is 3 seconds, but you can set the timeout to any value between 1 and 300 seconds.
To determine why your Lambda function is not working as expected:
You can test your code locally as you would any other Node.js function, or you can test it within the Lambda console using the console's test invoke functionality, or you can use the AWS CLI Invoke command. Each time the code is executed in response to an event, it writes a log entry into the log group associated with a Lambda function, which is /aws/lambda/.
If you see a timeout exceeded error in the log, your timeout setting exceeds the run time of your function code. This may be because the timeout is too low, or the code is taking too long to execute.
For solution:
Test your code with different memory settings.
If your code is taking too long to execute, it could be that it does not have enough compute resources to execute its logic. Try increasing the memory allocated to your function and testing the code again, using the Lambda console's test invoke functionality. You can see the memory used, code execution time, and memory allocated in the function log entries. Changing the memory setting can change how you are charged for duration. For information about pricing, see AWS Lambda.
Resource Link:
- Troubleshooting and Monitoring AWS Lambda Functions with Amazon CloudWatch
For testing, a full code example is given here: http://qiita.com/c9katayama/items/b9a30cdfaaa91cba23ad
来源：https://stackoverflow.com/questions/40741579/api-gatewaylambdavpc-timeout-issue