Backing up old clusters AFTER upgrading Postgresql - database

So, I was careless and upgraded Ubuntu from 18 to 20 -- thus postgresql from 10 to 12 -- WITHOUT making backups of my postgresql-10 cluster. Now that I'm looking into upgrading the cluster to work with 12, I'm realizing that was a mistake. Is there a way to back them up before attempting to upgrade them, now that postgres itself is already upgraded?
I could just copy the whole data folder and zip it up somewhere, but (a) that'd be a lot of disk space, and (b) I definitely don't yet understand postgres well enough to restore from those files.
(The last annoying thing here, which maybe deserves its own question, is that my pg10 data directory is on an external drive, which I'd like to keep using. Even if I can solve my backup problem, I'm not sure what the "easiest" way to do this is...)
EDIT: Actually I think my problem is a little different than I thought, and the postgres backup tools might still work for me. I will report back!

There is no supported way to downgrade PostgreSQL.
The best you can do is to take a plain format pg_dump and keep editing the file until you succed to load it into v10. It halps to split the dump into the pre-data, data and post-data sections.

It turns out I had two versions of Postgres installed simultaneously, so I was able to backup with a simple 'pg_dumpall' before upgrading the clusters. This manpage and this blogpost were both helpful in sorting things out.
Because I had a lot of onboard storage free I let pg_upgradecluster populate the default data folder, and then I copied it all over to my external, and edited the conf file to point back to that. (And then, yes, I made a backup of the upgraded cluster.)

Related

Can I temporarily install fresh Joomla and connect to old database while I fix it

My site is messed up and I am trying to fix it, and regardless of it I get help, it is going to take awhile likely, and it's really important that my site be live, even if it's a crappy version with just the articles and no template.
Would it not work to make a backup of the database, install Joomla fresh (the same version) and connect it to that duplicate database (then point my domain there) and then go back to working on fixing the current site that is live now? Are there any issues I should know about going in? There's a good chance the issues are related to the template or extensions (at least my understanding so far, see my other post for details on the issue) so I would think it would be faster to do this to get a working site rather than trying to turn off and on each extension, especially when I have to do it manually (and I don't know how yet) as I can't access the backend.
If this will work, do I choose the database when I install or just install empty and then change what database it connects to or do i install empty and import the tables (and how)? Still have to figure out if I can make a clone of the database and not all the files as it takes hours.
Thanks for the help, and if I should have appended this to the other post I apologize, but I figured its a separate issue.
First, ensure you have backups of both the files and the database. Then make a local copy of your site where you will work later.
The infection may lie:
in the Joomla core files, with extra content (which is usually fairly easy to spot, for example an eval of a large base64-encoded variable);
in extra files (keep in mind that even images could contain malicious code), these would be usually triggered outside of Joomla for spamming or other nefarious purposes
in the database content.
Fix:
Apply a fresh Joomla update package over your site; you will only fix n.1 above. This may restore some functionality for the first hour of survival.
Analyse the logs, and try to figure out how they got in. You need to step up security as obviously what you have is not enough.
Install a fresh Joomla, add all extensions that your site uses, copy the images folder, then connect it to a copy of the compromised database. This will fix n.1 and 2 above (as you got rid of any extra files). This may survive until they figure out you fixed it; but if you haven't patched your security, they will hack into your site again. Keep a copy of this, and restore as needed as you proceed with the following step.
Export the db to sql format (mysqldump or phpmyadmin may come in handy), then search for any xss traces, php code, javascripts that may have been injected. Since a complete control could take days, and assuming the malicious code links elsewhere, look for strings such as "https://" and "http://"; escape / as \/ and \\\/ to account for json-encoded data as well.
Once the db is clean, your local copy is reasonably safe; update all extensions and Joomla, and use it to restore the website until you fix your security.
It might work, i mean cloning the DB as far as joomla version is the same. It won't break like that, but may fail if files for extensions are not found. This is somewhat wrong, the question is how many extensions you are using and how much cleansing you need.
On the other side you mention that the site should be 'live'. Just do everything on localhost, test, fix templates, etc. Then if you're sure you're done, use akeeba backup and deploy new version to your server without long delays.
Any kind of cleansing needs some start.
You can clean the site while live, depends on complexity.
Clean might be done offline and deployed.
Sometimes import/export custom routines are needed, so you have to make own tools for everything. It occurs with large data, like when people used to made mess inside images folder or something like that.
4 ...
It's pointless to make copies of DB. You install the same version of Joomla on your local server, then you install the same template, you copy styles etc.
Then you import data with your own tools or paid ones. Estimated time is from few hours to few days, it's just data :)

Docker Like DB Deployment

I've just finished setting a dev environment where every developers /feature/, /bugfix/ and /hotfix/* git branches are automatically built and deployed to a freshly provisioned Windows Container which hosts the webapp and services creating a test environment, for each branch to be validated before merging into master.
While this is working quite nicely, I've still only got 1 dev db per developer which is used by all of their branches.
In an ideal world, I would like each of these test containers to use their own isolated db instance, however the db is currently at about 50gb at the smallest i can get it without going and tearing out historical data which is sometime useful.
What I would really like to do, is create a docker like image for this db and then spawn a new "container" from this image which only keeps track of the diff between it's changes an the original without ever altering the original db.
Is something like this even possible or does anyone have any ideas how I might achieve this db isolation, per container without having to create a full 50gb db for each?
Ok, So after much flailing around in the dark, I think I've finally come up with a solution. #ErikEJ, thanks, you started me off in the right direction. After looking into DB Snapshots on MSSQL, I found the only way to do writable snapshots seemed to be using vss and actually creating writable disk snapshots. This too led me down a long path of at first trying locally and failing, then trying to implement iscsi and still getting nowhere. Then I stumbled upon hyper-v snapshots and had a look at what was happening under the hood there and finally came across creating differencing VHD's. So basically my solution is as below.
Create VHD with a sanitised copy of my production DB mdf and ldf file in.
Then I create differencing vhds for each environment I need, mount the differencing vhds each in their own folder eg c:\db\Issue-1234 and create a new db DB_ISSUE-1234 by atatching to the files in these folders. Only the diffs are then stored and instead of having several 50-60gig copies of the db. I only have 1 and then the differencing vhds only store the difference.
I've just got this working with 2 or 3, so not sure how robust it is and how fast these differencing vhds are going to grow, but looking very promising so far and is allowing me to spin up multiple environments for testing purposes, extremely quickly (in fact all automated by scripts in deployment).
Hope this possibly helps someone else save some time one day and please let me know if anyone has figured out a more efficient/quicker/better way to do this :)

CiviCRM "database looks to have been partially upgraded"

I recently upgraded both Drupal and CiviCRM to the latest versions. Drupal works fine, and so does Civi except when I move to the Civi menu, I get a message that says "Database check failed - the database looks to have been partially upgraded. You may want to reload the database with the backup and try the upgrade process again." This happened earlier and reloading the most recent backup didn't help. We had to go back quite a ways before we found one that did, then had to reload a lot of data from .CSV files and by hand. I'd rather not go through with that again.
One thing we found when comparing the development site on my WAMP desktop (which was a new install that works well) with the one on my ISP's server is that the server version contained two MyISam-format files from, or generated by, CiviCase where Civi wants to see InnoDB-format files. My ISP, far more knowlegable than I am about MySQL, converted these two files two InnoDB and the problem remains. This leaves me with two questions:
could the MyISam files be the source of the "incomplete upgrade"? and
is there some way to reset a flag that tells Civi that the database is incomplete or to run the database check manually?
Thanks for any help. Civi seems to work OK as is, but the error message will be disturbing to my end users.
That message happens when you have begun the CiviCRM database upgrade but it hasn't finished. CiviCRM edits the version number in the civicrm_domain table to flag that you're in the middle of an upgrade, and when the upgrade completes, it should remove that.
The simple way to remove the message is to go edit that in the database, but it gets set there for a reason: your database upgrade never completed.
You should restore everything to the last version where it all was working--restore both the code and the database. Play around for a bit and make sure nothing funny is happening.
Run a normal CiviCRM upgrade, replacing the files and running the upgrade script. Take note of anything that seems funny when the upgrade script runs. You might try doing a minor upgrade--just a point release--simply to be sure that any upgrade is working fine.
At this point, you should either have no problems or a much more detailed problem.
Finally, please note that there is now a CiviCRM-specific StackExchange site, which is where you'll find the most CiviCRM experts to answer your questions.

Making Postgres SQL minimal size. How?

I want to cut Postgres to its minimal size for purpose of including just database function with my application. I'm using Portable Postgres found on internet.
Any suggestions what I can delete from Postgres installation which is not needed for normal database use?
You can delete all the standalone tools in /bin - it can all be done with psql. Keep anything that starts wth pg_, postgres and initdb.
You can probably delete a bunch of conversions in lib/ (the some_and_some.so) files, but probably not until after you've initdb'ed. And be careful not to delete one you'll be using at some point - they are dynamically loaded so you won't notice until a client connects with a different encoding for example.
But note that this probably won't get you much - on my system with debug enabled etc, the binaries take 17Mb. The clean data directory with no data at all in it takes 33Mb, about twice as much. Which you will need if you're going to be able to use your database..

How can I put a database under git (version control)?

I'm doing a web app, and I need to make a branch for some major changes, the thing is, these changes require changes to the database schema, so I'd like to put the entire database under git as well.
How do I do that? is there a specific folder that I can keep under a git repository? How do I know which one? How can I be sure that I'm putting the right folder?
I need to be sure, because these changes are not backward compatible; I can't afford to screw up.
The database in my case is PostgreSQL
Edit:
Someone suggested taking backups and putting the backup file under version control instead of the database. To be honest, I find that really hard to swallow.
There has to be a better way.
Update:
OK, so there' no better way, but I'm still not quite convinced, so I will change the question a bit:
I'd like to put the entire database under version control, what database engine can I use so that I can put the actual database under version control instead of its dump?
Would sqlite be git-friendly?
Since this is only the development environment, I can choose whatever database I want.
Edit2:
What I really want is not to track my development history, but to be able to switch from my "new radical changes" branch to the "current stable branch" and be able for instance to fix some bugs/issues, etc, with the current stable branch. Such that when I switch branches, the database auto-magically becomes compatible with the branch I'm currently on.
I don't really care much about the actual data.
Take a database dump, and version control that instead. This way it is a flat text file.
Personally I suggest that you keep both a data dump, and a schema dump. This way using diff it becomes fairly easy to see what changed in the schema from revision to revision.
If you are making big changes, you should have a secondary database that you make the new schema changes to and not touch the old one since as you said you are making a branch.
I'm starting to think of a really simple solution, don't know why I didn't think of it before!!
Duplicate the database, (both the schema and the data).
In the branch for the new-major-changes, simply change the project configuration to use the new duplicate database.
This way I can switch branches without worrying about database schema changes.
EDIT:
By duplicate, I mean create another database with a different name (like my_db_2); not doing a dump or anything like that.
Use something like LiquiBase this lets you keep revision control of your Liquibase files. you can tag changes for production only, and have lb keep your DB up to date for either production or development, (or whatever scheme you want).
Irmin (branching + time travel)
Flur.ee (immutable + time travel + graph query)
XTDB (formerly called 'CruxDB') (time travel + query)
TerminusDB (immutable + branching + time travel + Graph Query!)
DoltDB (branching + time-travel + SQL query)
Quadrable (branching + remote state verification)
EdgeDB (no real time travel, but migrations derived by the compiler after schema changes)
Migra (diffing for Postgres schemas/data. Auto-generate migration scripts, auto-sync db state)
ImmuDB (immutable + time-travel)
I've come across this question, as I've got a similar problem, where something approximating a DB based Directory structure, stores 'files', and I need git to manage it. It's distributed, across a cloud, using replication, hence it's access point will be via MySQL.
The gist of the above answers, seem to similarly suggest an alternative solution to the problem asked, which kind of misses the point, of using Git to manage something in a Database, so I'll attempt to answer that question.
Git is a system, which in essence stores a database of deltas (differences), which can be reassembled, in order, to reproduce a context. The normal usage of git assumes that context is a filesystem, and those deltas are diff's in that file system, but really all git is, is a hierarchical database of deltas (hierarchical, because in most cases each delta is a commit with at least 1 parents, arranged in a tree).
As long as you can generate a delta, in theory, git can store it. The problem is normally git expects the context, on which it's generating delta's to be a file system, and similarly, when you checkout a point in the git hierarchy, it expects to generate a filesystem.
If you want to manage change, in a database, you have 2 discrete problems, and I would address them separately (if I were you). The first is schema, the second is data (although in your question, you state data isn't something you're concerned about). A problem I had in the past, was a Dev and Prod database, where Dev could take incremental changes to the schema, and those changes had to be documented in CVS, and propogated to live, along with additions to one of several 'static' tables. We did that by having a 3rd database, called Cruise, which contained only the static data. At any point the schema from Dev and Cruise could be compared, and we had a script to take the diff of those 2 files and produce an SQL file containing ALTER statements, to apply it. Similarly any new data, could be distilled to an SQL file containing INSERT commands. As long as fields and tables are only added, and never deleted, the process could automate generating the SQL statements to apply the delta.
The mechanism by which git generates deltas is diff and the mechanism by which it combines 1 or more deltas with a file, is called merge. If you can come up with a method for diffing and merging from a different context, git should work, but as has been discussed you may prefer a tool that does that for you. My first thought towards solving that is this https://git-scm.com/book/en/v2/Customizing-Git-Git-Configuration#External-Merge-and-Diff-Tools which details how to replace git's internal diff and merge tool. I'll update this answer, as I come up with a better solution to the problem, but in my case I expect to only have to manage data changes, in-so-far-as a DB based filestore may change, so my solution may not be exactly what you need.
There is a great project called Migrations under Doctrine that built just for this purpose.
Its still in alpha state and built for php.
http://docs.doctrine-project.org/projects/doctrine-migrations/en/latest/index.html
Take a look at RedGate SQL Source Control.
http://www.red-gate.com/products/sql-development/sql-source-control/
This tool is a SQL Server Management Studio snap-in which will allow you to place your database under Source Control with Git.
It's a bit pricey at $495 per user, but there is a 28 day free trial available.
NOTE
I am not affiliated with RedGate in any way whatsoever.
I've released a tool for sqlite that does what you're asking for. It uses a custom diff driver leveraging the sqlite projects tool 'sqldiff', UUIDs as primary keys, and leaves off the sqlite rowid. It is still in alpha so feedback is appreciated.
Postgres and mysql are trickier, as the binary data is kept in multiple files and may not even be valid if you were able to snapshot it.
https://github.com/cannadayr/git-sqlite
I want to make something similar, add my database changes to my version control system.
I am going to follow the ideas in this post from Vladimir Khorikov "Database versioning best practices". In summary i will
store both its schema and the reference data in a source control system.
for every modification we will create a separate SQL script with the changes
In case it helps!
You can't do it without atomicity, and you can't get atomicity without either using pg_dump or a snapshotting filesystem.
My postgres instance is on zfs, which I snapshot occasionally. It's approximately instant and consistent.
I think X-Istence is on the right track, but there are a few more improvements you can make to this strategy. First, use:
$pg_dump --schema ...
to dump the tables, sequences, etc and place this file under version control. You'll use this to separate the compatibility changes between your branches.
Next, perform a data dump for the set of tables that contain configuration required for your application to operate (should probably skip user data, etc), like form defaults and other data non-user modifiable data. You can do this selectively by using:
$pg_dump --table=.. <or> --exclude-table=..
This is a good idea because the repo can get really clunky when your database gets to 100Mb+ when doing a full data dump. A better idea is to back up a more minimal set of data that you require to test your app. If your default data is very large though, this may still cause problems though.
If you absolutely need to place full backups in the repo, consider doing it in a branch outside of your source tree. An external backup system with some reference to the matching svn rev is likely best for this though.
Also, I suggest using text format dumps over binary for revision purposes (for the schema at least) since these are easier to diff. You can always compress these to save space prior to checking in.
Finally, have a look at the postgres backup documentation if you haven't already. The way you're commenting on backing up 'the database' rather than a dump makes me wonder if you're thinking of file system based backups (see section 23.2 for caveats).
What you want, in spirit, is perhaps something like Post Facto, which stores versions of a database in a database. Check this presentation.
The project apparently never really went anywhere, so it probably won't help you immediately, but it's an interesting concept. I fear that doing this properly would be very difficult, because even version 1 would have to get all the details right in order to have people trust their work to it.
This question is pretty much answered but I would like to complement X-Istence's and Dana the Sane's answer with a small suggestion.
If you need revision control with some degree of granularity, say daily, you could couple the text dump of both the tables and the schema with a tool like rdiff-backup which does incremental backups. The advantage is that instead of storing snapshots of daily backups, you simply store the differences from the previous day.
With this you have both the advantage of revision control and you don't waste too much space.
In any case, using git directly on big flat files which change very frequently is not a good solution. If your database becomes too big, git will start to have some problems managing the files.
Here is what i am trying to do in my projects:
separate data and schema and default data.
The database configuration is stored in configuration file that is not under version control (.gitignore)
The database defaults (for setting up new Projects) is a simple SQL file under version control.
For the database schema create a database schema dump under the version control.
The most common way is to have update scripts that contains SQL Statements, (ALTER Table.. or UPDATE). You also need to have a place in your database where you save the current version of you schema)
Take a look at other big open source database projects (piwik,or your favorite cms system), they all use updatescripts (1.sql,2.sql,3.sh,4.php.5.sql)
But this a very time intensive job, you have to create, and test the updatescripts and you need to run a common updatescript that compares the version and run all necessary update scripts.
So theoretically (and thats what i am looking for) you could
dumped the the database schema after each change (manually, conjob, git hooks (maybe before commit))
(and only in some very special cases create updatescripts)
After that in your common updatescript (run the normal updatescripts, for the special cases) and then compare the schemas (the dump and current database) and then automatically generate the nessesary ALTER Statements. There some tools that can do this already, but haven't found yet a good one.
What I do in my personal projects is, I store my whole database to dropbox and then point MAMP, WAMP workflow to use it right from there.. That way database is always up-to-date where ever I need to do some developing. But that's just for dev! Live sites is using own server for that off course! :)
Storing each level of database changes under git versioning control is like pushing your entire database with each commit and restoring your entire database with each pull.
If your database is so prone to crucial changes and you cannot afford to loose them, you can just update your pre_commit and post_merge hooks.
I did the same with one of my projects and you can find the directions here.
That's how I do it:
Since your have free choise about DB type use a filebased DB like e.g. firebird.
Create a template DB which has the schema that fits your actual branch and store it in your repository.
When executing your application programmatically create a copy of your template DB, store it somewhere else and just work with that copy.
This way you can put your DB schema under version control without the data. And if you change your schema you just have to change the template DB
We used to run a social website, on a standard LAMP configuration. We had a Live server, Test server, and Development server, as well as the local developers machines. All were managed using GIT.
On each machine, we had the PHP files, but also the MySQL service, and a folder with Images that users would upload. The Live server grew to have some 100K (!) recurrent users, the dump was about 2GB (!), the Image folder was some 50GB (!). By the time that I left, our server was reaching the limit of its CPU, Ram, and most of all, the concurrent net connection limits (We even compiled our own version of network card driver to max out the server 'lol'). We could not (nor should you assume with your website) put 2GB of data and 50GB of images in GIT.
To manage all this under GIT easily, we would ignore the binary folders (the folders containing the Images) by inserting these folder paths into .gitignore. We also had a folder called SQL outside the Apache documentroot path. In that SQL folder, we would put our SQL files from the developers in incremental numberings (001.florianm.sql, 001.johns.sql, 002.florianm.sql, etc). These SQL files were managed by GIT as well. The first sql file would indeed contain a large set of DB schema. We don't add user-data in GIT (eg the records of the users table, or the comments table), but data like configs or topology or other site specific data, was maintained in the sql files (and hence by GIT). Mostly its the developers (who know the code best) that determine what and what is not maintained by GIT with regards to SQL schema and data.
When it got to a release, the administrator logs in onto the dev server, merges the live branch with all developers and needed branches on the dev machine to an update branch, and pushed it to the test server. On the test server, he checks if the updating process for the Live server is still valid, and in quick succession, points all traffic in Apache to a placeholder site, creates a DB dump, points the working directory from 'live' to 'update', executes all new sql files into mysql, and repoints the traffic back to the correct site. When all stakeholders agreed after reviewing the test server, the Administrator did the same thing from Test server to Live server. Afterwards, he merges the live branch on the production server, to the master branch accross all servers, and rebased all live branches. The developers were responsible themselves to rebase their branches, but they generally know what they are doing.
If there were problems on the test server, eg. the merges had too many conflicts, then the code was reverted (pointing the working branch back to 'live') and the sql files were never executed. The moment that the sql files were executed, this was considered as a non-reversible action at the time. If the SQL files were not working properly, then the DB was restored using the Dump (and the developers told off, for providing ill-tested SQL files).
Today, we maintain both a sql-up and sql-down folder, with equivalent filenames, where the developers have to test that both the upgrading sql files, can be equally downgraded. This could ultimately be executed with a bash script, but its a good idea if human eyes kept monitoring the upgrade process.
It's not great, but its manageable. Hope this gives an insight into a real-life, practical, relatively high-availability site. Be it a bit outdated, but still followed.
Update Aug 26, 2019:
Netlify CMS is doing it with GitHub, an example implementation can be found here with all information on how they implemented it netlify-cms-backend-github
I say don't. Data can change at any given time. Instead you should only commit data models in your code, schema and table definitions (create database and create table statements) and sample data for unit tests. This is kinda the way that Laravel does it, committing database migrations and seeds.
I would recommend neXtep (Link removed - Domain was taken over by a NSFW-Website) for version controlling the database it has got a good set of documentation and forums that explains how to install and the errors encountered. I have tested it for postgreSQL 9.1 and 9.3, i was able to get it working for 9.1 but for 9.3 it doesn't seems to work.
Use a tool like iBatis Migrations (manual, short tutorial video) which allows you to version control the changes you make to a database throughout the lifecycle of a project, rather than the database itself.
This allows you to selectively apply individual changes to different environments, keep a changelog of which changes are in which environments, create scripts to apply changes A through N, rollback changes, etc.
I'd like to put the entire database under version control, what
database engine can I use so that I can put the actual database under
version control instead of its dump?
This is not database engine dependent. By Microsoft SQL Server there are lots of version controlling programs. I don't think that problem can be solved with git, you have to use a pgsql specific schema version control system. I don't know whether such a thing exists or not...
Use a version-controlled database, of which there are now several.
https://www.dolthub.com/blog/2021-09-17-database-version-control/
These products don't apply version control on top of another type of database -- they are their own database engines that support version control operations. So you need to migrate to them or start building on them in the first place.
I write one of them, DoltDB, which combines the interfaces of MySQL and Git. Check it out here:
https://github.com/dolthub/dolt
I wish it were simpler. Checking in the schema as a text file is a good start to capture the structure of the DB. For the content, however, I have not found a cleaner, better method for git than CSV files. One per table. The DB can then be edited on multiple branches and merges extremely well.

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