112 votes
Accepted

AWS RDS connection limits

AWS RDS max_connections limit variable is based on Instance type, so you can upgrade your RDS or make more replica. The RDS types with max_connections limit: t2.micro 66 t2.small 150 m3.medium 296 ...
  • 1,288
60 votes
Accepted

unable to connect to public postgresql rds instance

The issue was that the inbound rule in the Security Group specified a security group as the source. Changing it to a CIDR that included my IP address fixed the issue. Open the database security ...
53 votes

AWS RDS connection limits

You can change the max_connections value by either updating the default parameter policy or create a new one - I'd suggest going with the latter. Go to RDS Parameter Groups Create a new Parameter ...
  • 531
39 votes

How do you recover you RDS master user username?

The master username is now listed in the RDS Dashboard. Select the "Instances" listing and expand the DB instance. Press the looking glass tab on the left. The master username is listed in the left ...
  • 491
31 votes

Why can't I create a superuser in AWS Postgresql instance?

RDS instances are managed by Amazon. As such, to prevent you from breaking things like replication, your users - even the root user you set up when you create the instance - will not have full ...
  • 32.6k
30 votes

What is "freeable memory"?

It is basically available RAM. See answer from AWS here https://forums.aws.amazon.com/thread.jspa?threadID=209720 and the official documentation is here http://docs.aws.amazon.com/AmazonRDS/latest/...
  • 598
24 votes
Accepted

Why is my "volume bytes used" always increasing on my Amazon Aurora cluster?

There are multiple things at play here... Each table is stored in its own tablespace By default, the parameter group for Aurora clusters (named default.aurora5.6) defines innodb_file_per_table = ON. ...
23 votes
Accepted

Unable to connect to RDS instance from outside VPC (ERROR 2003 (HY000) Can't connect to MySQL Server)

For an RDS instance in VPC to "publicly" (Internet) accessible, all of the subnets it is attached to must be "public" -- as opposed to "private" -- subnets of the VPC. A public subnet is essentially ...
19 votes

How do you recover you RDS master user username?

It is 2019 now. It is 'Databases' on the sidebar, 'Configuration' on the navigation bar. And look for username.
  • 299
18 votes

unable to connect to public postgresql rds instance

Was facing similar issue, and this is how I resolved it: Click on the security group for the RDS instance and check the inbound rules. You might see something like this: Have to set the IP range to ...
16 votes
Accepted

How to Rename a Database on a SQL Server Amazon RDS Instance?

RDS has recently added a stored procedure to accomplish this: EXEC rdsadmin.dbo.rds_modify_db_name N'<OldName>', N'<NewName>' Source: https://docs.aws.amazon.com/AmazonRDS/latest/...
15 votes

Highest value of max_connections in AWS RDS micro instance

Here's what you can do to change max_connections or any other parameter in an AWS RDS (mysql) instance: From RDS console go to Parameter Groups Create a new parameter group based on the default group ...
  • 261
14 votes
Accepted

Is it possible to force Re-creation of EC2::Instance or RDS::DBInstance in amazon cloudformation?

For instance store-backed EC2 instances, one trick is to add a comment to the user data script containing a version number, date, or similar, then change that whenever you want the instance recreated: ...
  • 485
14 votes
Accepted

Reset slow_log tables in RDS of AWS

I got a solution Amazon RDS will not give you SSH access to its database server. That means you don’t have the opportunity to view any of the log files, even the slow query log, for the database. But ...
  • 281
14 votes

AWS RDS connection limits

Actual info for Postgresql t3-instances (default.postgres10 parameter group): db.t3.micro - 112 max_connections db.t3.small - 225 max_connections db.t3.medium - 450 max_connections db.t3.large - 901 ...
14 votes
Accepted

"Update Your Amazon RDS SSL/TLS Certificates by October 31, 2019"

The default sslmode for PostgreSQL is prefer which means it will encrypt the connection with the certificate provided by the server but will not verify it. If I were to change the sslmode setting to ...
12 votes

How to move RDS database to different VPC

Amazon has recently issued a press release announcing that you can now change the VPC for existing RDS instances: You can now easily change the Amazon Virtual Private Cloud (Amazon VPC) used by your ...
12 votes
Accepted

How to check via aws cli if a specific rds instance exists?

Notice the constraint in the docs when using --db-instance-indentifier: --db-instance-identifier (string) The user-supplied instance identifier. If this parameter is specified, information from ...
  • 7,435
11 votes

Why can't I connect to Amazon RDS after setting it up?

A lot of talk here about security groups, but also check: Do the associated Subnets seem properly configured? Are the Subnets part of a Routing Group that seems properly configured (Internet Gateway ...
11 votes

Can't find the private IP address for my Amazon-RDS instance

You can find a required info in the EC2 console. Go to RDS Console Select Databases and find required DB Instance. Open it and find details Go to Connectivity & security and find VPC ...
11 votes
Accepted

Does RDS in private subnet inside AWS VPC need a NAT instance/gateway?

General Rule NAT provides outgoing internet access, and does not allow incoming connections. Note that NAT gateway is a managed service, and is generally preferred over a NAT instance. RDS does not ...
  • 30.8k
10 votes
Accepted

AWS RDS MySQL vs Aurora

The technical differences are summarised nicely in this SlideShare - http://www.slideshare.net/AmazonWebServices/amazon-aurora-amazons-new-relational-database-engine It's really quite a different ...
10 votes
Accepted

Any drawback in using AWS RDS "dev/test" instance for production?

There is no persistent difference between choosing the Development and Production options in the new RDS instance wizard. Selecting the options simply chooses different defaults on the following pages:...
  • 9,804
10 votes

Diagnosing low disk space error from PostgreSQL despite low disk usage

You are getting this error because PostgreSQL is running out of space to write a temporary file. You have at least one query that causes the database to occasionally write out a temporary table that ...
  • 276
10 votes
Accepted

AWS CIDR is not within the CIDR ranges of VPC

AWS is correct. 10.0.0.0/24 is 10.0.0.0 to 10.0.0.255. You're trying to add something outside this range, 10.0.1.x You probably meant to create your VPC as 10.0.0.0/16.
  • 30.8k
9 votes

Deleting log files from an AWS RDS Postgres instance

This is controlled through the use of "Parameter Group" settings. 1) In the RDS dashboard, go to "Parameter Groups" 2) Create a new parameter group, make sure the "Group Family" is set to postgres9....
  • 153
9 votes

Highest value of max_connections in AWS RDS micro instance

It appears that things have changed since the accepted answer. After seeing this thread I ran a test on a db.m3.medium RDS MySQL instance with max_connection manually set to 2000 using DB Parameter ...
  • 223
9 votes

How do you recover you RDS master user username?

With the new updated RDS UI, the username is present in the Details section of the Instance Information screen. From the List of your running Instances, click an instance name to see information ...
9 votes

What is "freeable memory"?

From this Q&A on the AWS Forum: The freeable memory includes the amount of physical memory left unused by the system plus the total amount of buffer or page cache memory that are free and ...
  • 1,055
9 votes

Downtime for increasing AWS RDS storage?

As you are only increasing storage size and not changing the instance type or anything else there shouldn't be any downtime, but there could be 'degraded performance' while the operation is carried ...
  • 191

Only top scored, non community-wiki answers of a minimum length are eligible