I'm trying to migrate a PostgreSQL DB persisted on cloud (on DO droplet) to RDS using AWS Database Migration Service (DMS).
I've successfully configured the replication instance and endpoints.
I've created a task with Migrate existing data and replicate ongoing changes. When I start the task it shows some error ERROR: could not access file "test_decoding": No such file or directory.
I've tried to create a replication slot manually on my DB console it throws the same error.
I've followed the procedures which was suggested on the DMS documentation for Postgres
I'm using PostgreSQL 9.4.6 on my source endpoint.
I presume that the problem is the output plugin test_decoding was not accessible to do the replication.
Please assist me to resolve this. Thanks in advance!
You must install postgresql-contrib additional supplied modules on Your source endpoint.
If it is installed, make sure, directory where test_decoding module located is the same with directory where PostgreSQL expect it.
In *nix, You can check module directory by command:
pg_config --pkglibdir
If it is not the same, copy module, or make symlink, or some other solution You prefer.
Related
I'm trying to connect to an RDS cluster in AWS that's an Aurora PostgreSQL database. It's a brand-new database that I created along with the instances that I have Jira deployed to. However, when I try to connect to the instance from the Jira configuration screen I get this error
You have specified a database that is not empty, please specify an empty database.
I haven't touched this database at all, why is it giving me this error? I have one read and one write database in my cluster and the "hostname" is the endpoint for my write database, which is what the docs say. Could this be an issue with the Jira version I'm using?
This is the download link I'm using in my user-data script to install Jira. I'm also using PostgreSQL version 12.11
https://www.atlassian.com/software/jira/downloads/binary/atlassian-servicedesk-4.19.1-x64.bin
I switched to a different PostgreSQL version and now it's working.
PostgreSQL version 12.11 was giving me the error and switching to version 13.7 works as expected.
I've installed Bareos 20.0.1 on Ubuntu 20.04.3 according to their documentations here.
I'm trying to backup a remote PostgreSQL database and apparently, there are three possible scenarios and the pros of the PostgreSQL Plugin (third solution), makes it the obvious choice.
Following the PostgreSQL Plugin documentations, in the Prerequisites for the PostgreSQL Plugin section, there is a line saying:
The plugin must be installed on the same host where the PostgreSQL database runs.
Now what I'm failing to understand is that, if I'm supposed to install the plugin on my database node, how will the bareos machine and the plugin on the db machine communicate?
Furthermore, I've checked out the source code for this module on their GitHub, and I see that the plugin source code tries to find files locally and that is a proof to the aforementioned statement.
In a desperate act, I tried installing the plugin and its dependencies on the bareos node and I keep getting the error Error: python3-fd-mod: Could not read Label File /var/lib/postgresql/13/main/backup_label which is actually trying to find the backup_label file in the bareos node.
Here is the configuration for my fileset:
FileSet {
Name = "psql"
Include {
Options {
compression=GZIP
signature = MD5
}
Plugin = "python"
":module_path=/usr/lib/bareos/plugins"
":module_name=bareos-fd-postgres"
":postgresDataDir=/var/lib/postgresql/13/main"
":walArchive=/var/lib/postgresql/13/wal_archive/"
":dbHost=DATABASE_DNS"
":dbuser=DATABASE_USER"
}
}
Note that the plugin document specifies the dbHost parameter as:
useful, if socket is not in default location. Specify socket-directory with a leading / here
However, since I'm trying a remote database, I'm using the DNS address of the remote database. I verified the bareos connection to database and made sure the backup_label file gets created while the PostgreSQL backup job runs.
I'll be happy to provide more details if necessary. Appreciate any help or even guesses :-D
I have a need to load data from S3 to Postgres RDS (around 50-100 GB) I don't have the option to use AWS Data Pipeline and I am looking for something similar to using the COPY command to load data in S3 into Amazon Redshift.
I would appreciate any suggestions on how I can accomplish this.
Originally, this answer was trying to use the S3 to Postgres RDS Functionality. That whole enterprise failed (see below).
The way I have finally been able to do this is:
Set-up an EC2 instance with psql installed (see below near end of post)
Copy the relevant CSVs to import from S3 to the local instance
Use the psql /copy command to import the files up
This last part is really, really important. If you use the SQL COPY command the entire RDS Postgres role structure will frustrate you to no end. It has a wonky SUPERRDSADMIN role which is not very super at all. However, if you use the psql /copy commany you apparently can do anything. I have confirmed this be the case and have started my uploads succesfully. I will come back and re-edit this post (time permitting) to add relevant documentation steps for the above.
Caveat Emptor: The post below was all the original work I had done trying to get this implemented. I don't want to bury the lead despite multiple efforts (including what can only be described as pathetic tech support from AWS) I don't believe that this feature is ready for prime time. Despite a very simple test environment, easy to replicate, AWS has not provided an effective way to not get the copy statement to crap out as follows:
The actual call to aws_s3.table_import_from_s3(...) is reporting a permission problem between RDS and S3. From my research work with psql this appears to be a C library, probably installed by AWS.
NOTICE: CURL error code: 28 when attempting to validate pre-signed URL, 1 attempt(s) remaining
NOTICE: HINT: make sure your instance is able to connect with S3.
S3 to Postgres RDS Functionality Now Added
On 2019-04-24 AWS released functionality allowing a Postgres RDS to load directly from S3. You can read the announcement here, and see the documentation page here.
I am sharing with the OP because this appears to be the AWS supported way of solving the question posed.
Key summary points:
Requires Postgres 11.1 or greater
Need access to psql and the ability to connect it to the RDS instance
Need to install the aws_s3 extension which pulls in aws_commons.
You can get to the S3 bucket by specifying credentials or by assigning IAM roles to RDS
It advertises supporting all of the same data formats as the postgres COPY command
It currently only appears to support a single file at a time (ie no regex)
The instructions are fairly detailed and provide a variety of paths to configuring (AWS CLI scripts, Console instructions, etc). Additionally, the option to use your IAM keys rather than have to set-up roles is nice.
I did not find a way to download just psql, so I had to bring down a full postgres install down to my mac, but that was no big deal with brew:
brew install postgres
and since the DB service does not get activated it is the quickest way to get psql.
Update: Decided that having psql on my mac was a security hole, port forwarding, etc. I found that there is a simple Postgres install available for AMI Linux 2 under the AMI Extras rubric. The install command is fairly simple on your ami instance type.
sudo amazon-linux-extras install postgresql10
psql is fairly easy to use, however, important to keep in mind that any instructions to psql itself are escaped by a \. Documentation on psql can be found here. Recommend going through it at least once before executing the AWS recommended scripts.
To the extent you run tight security and have access to your RDS instances seriously restricted (which I do) don't forget to open up the ports from your AMI instance running Postgres to your RDS instance.
If your preference is a GUI then you can try to use PGAdmin4. It is the AWS recommended way of connecting to RDS Postgres instances according to the docs. I was unable to get any of the SSH tunneling features to work (which is why I ended up doing the localhost SSH mapping that I used for psql). I also found it to be rather buggy in other ways. Reading reviews of the product it seems that version 4 may not be the stablest of releases.
http://docs.aws.amazon.com/redshift/latest/dg/t_loading-tables-from-s3.html
Use the COPY command to load a table in parallel from data files on
Amazon S3. You can specify the files to be loaded by using an Amazon
S3 object prefix or by using a manifest file.
The syntax to specify the files to be loaded by using a prefix is as
follows:
copy <table_name> from 's3://<bucket_name>/<object_prefix>'
authorization;
update
Another option is to mount s3 and use direct path to the csv with COPY command. I'm not sure If it will hold 100GB effectively, but worth of trying. Here is some list of options on software.
Yet another option would be "parsing" s3 file part by part with something described here to a file and COPY from named pipe, described here
And the most obvious option to just download file to local storage and use COPY I don't cover at all
Also worth of mentioning would be s3_fdw (status unstable). Readme is very laconic, but I assume you could create a foreign table leading to s3 file. Which itself means you can load data to other relation...
AWS RDS PostgreSQL instance able to connect from another PostgreSQL client but not able to see data directory and configuration files .is there any way to edit/view data directory and configuration files
If you want to work with file system, use EC2 instances with postgres installed and configured as you wish. Neither postgres.conf, nor hba.conf cant be edited directly on file system.
http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/Appendix.PostgreSQL.CommonDBATasks.html#Appendix.PostgreSQL.CommonDBATasks.Parameters
Instead use amazon provided interface to change supported parameters or use SET command where possible...
SQL distributes pre-initialized catalog cluster but for postgresql we need initialize cluster using initdb and a network service account. It fails in few cases and causing bit of misery!
Can initialize cluster ourselves and distribute pre-initialized cluster?
Thanks
The "cluster" (or data directory) depends on the operating system and the architecture. So a data directory that was initialized with initdb on a 32bit Linux will not work on a 64bit Windows.
But you don't need to do that. A service account is only necessary if you want to run PostgreSQL as a service.
You can easily use the ZIP distribution to install and start Postgres without the need for a full-fledge installation or a service account.
The steps to do so are:
Unzip the binaries
Run initdb pointing it to the directory where the database cluster should be created.
Run pg_ctl to start the server.
Note that the steps 2) and 3) must be run using the same user, otherwise the server will have no priviliges to write to the data directory.
These steps can easily be put into a batch file or shell script.
Hard to understand your question, but I think you are talking about the Windows installer for PostgreSQL. Right? What version, what installer, what about error messages, loggings, etc. ?
The installer can be found here.
SQL = database language, SQL Server =
Microsoft database product