AWS: Why does my RDS instance keep starting after I turned it off? - database

Question

I have an RDS database instance on AWS and have turned it off for now. However, every few days it starts up on its own. I don't have any other services running right now.
There is this event in my RDS log:
"DB instance is being started due to it exceeding the maximum allowed time being stopped."
Why is there a limit to how long my RDS instance can be stopped? I just want to put my project on hold for a few weeks, but AWS won't let me turn off my DB? It costs $12.50/mo to have it sit idle, so I don't want to pay for this, and I certainly don't want AWS starting an instance for me that does not get used.
Please help!

Answer 1

That's a limitation of this new feature.
You can stop an instance for up to 7 days at a time. After 7 days, it will be automatically started. For more details on stopping and starting a database instance, please refer to Stopping and Starting a DB Instance in the Amazon RDS User Guide.
You can setup a cron job to stop the instance again after 7 days. You can also change to a smaller instance size to save money.
Another option is the upcoming Aurora Serverless which stops and starts for you automatically. It might be more expensive than a dedicated instance when running 24/7.
Finally, there is always Heroku which gives you a free database instance that starts and stops itself with some limitations.
You can also try saving the following CloudFormation template as KeepDbStopped.yml and then deploy with this command:
aws cloudformation deploy --template-file KeepDbStopped.yml --stack-name stop-db --capabilities CAPABILITY_IAM --parameter-overrides DB=arn:aws:rds:us-east-1:XXX:db:XXX
Make sure to change arn:aws:rds:us-east-1:XXX:db:XXX to your RDS ARN.
Description: Automatically stop RDS instance every time it turns on due to exceeding the maximum allowed time being stopped
Parameters:
DB:
Description: ARN of database that needs to be stopped
Type: String
AllowedPattern: arn:aws:rds:[a-z0-9\-]+:[0-9]+:db:[^:]*
Resources:
DatabaseStopperFunction:
Type: AWS::Lambda::Function
Properties:
Role: !GetAtt DatabaseStopperRole.Arn
Runtime: python3.6
Handler: index.handler
Timeout: 20
Code:
ZipFile:
Fn::Sub: |
import boto3
import time
def handler(event, context):
print("got", event)
db = event["detail"]["SourceArn"]
id = event["detail"]["SourceIdentifier"]
message = event["detail"]["Message"]
region = event["region"]
rds = boto3.client("rds", region_name=region)
if message == "DB instance is being started due to it exceeding the maximum allowed time being stopped.":
print("database turned on automatically, setting last seen tag...")
last_seen = int(time.time())
rds.add_tags_to_resource(ResourceName=db, Tags=[{"Key": "DbStopperLastSeen", "Value": str(last_seen)}])
elif message == "DB instance started":
print("database started (and sort of available?)")
last_seen = 0
for t in rds.list_tags_for_resource(ResourceName=db)["TagList"]:
if t["Key"] == "DbStopperLastSeen":
last_seen = int(t["Value"])
if time.time() < last_seen + (60 * 20):
print("database was automatically started in the last 20 minutes, turning off...")
time.sleep(10) # even waiting for the "started" event is not enough, so add some wait
rds.stop_db_instance(DBInstanceIdentifier=id)
print("success! removing auto-start tag...")
rds.add_tags_to_resource(ResourceName=db, Tags=[{"Key": "DbStopperLastSeen", "Value": "0"}])
else:
print("ignoring manual database start")
else:
print("error: unknown database event!")
DatabaseStopperRole:
Type: AWS::IAM::Role
Properties:
AssumeRolePolicyDocument:
Version: '2012-10-17'
Statement:
- Action:
- sts:AssumeRole
Effect: Allow
Principal:
Service:
- lambda.amazonaws.com
ManagedPolicyArns:
- arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole
Policies:
- PolicyName: Notify
PolicyDocument:
Version: '2012-10-17'
Statement:
- Action:
- rds:StopDBInstance
Effect: Allow
Resource: !Ref DB
- Action:
- rds:AddTagsToResource
- rds:ListTagsForResource
- rds:RemoveTagsFromResource
Effect: Allow
Resource: !Ref DB
Condition:
ForAllValues:StringEquals:
aws:TagKeys:
- DbStopperLastSeen
DatabaseStopperPermission:
Type: AWS::Lambda::Permission
Properties:
Action: lambda:InvokeFunction
FunctionName: !GetAtt DatabaseStopperFunction.Arn
Principal: events.amazonaws.com
SourceArn: !GetAtt DatabaseStopperRule.Arn
DatabaseStopperRule:
Type: AWS::Events::Rule
Properties:
EventPattern:
source:
- aws.rds
detail-type:
- "RDS DB Instance Event"
resources:
- !Ref DB
detail:
Message:
- "DB instance is being started due to it exceeding the maximum allowed time being stopped."
- "DB instance started"
Targets:
- Arn: !GetAtt DatabaseStopperFunction.Arn
Id: DatabaseStopperLambda
It has worked for at least one person. If you have issues please report here.