I'm using Google Compute Instances to run several websites and am looking for a way to automatically backup/snapshot instances that would allow me to rollback in the event of a major error.
Assuming that your servers will restart after a reboot, a snapshot of your VM disks would make it easy to restore to a previous backup, or to clone a server onto a second host if you want to pre-stage some changes before making them live.
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I am dealing with the infrastructure for a new project. It is a standard Laravel stack = PHP, SQL server, and Nginx. For the PHP + Nginx part, we are using Kubernetes cluster - so scaling and blue/green deployments are taken care of.
When it comes to the database I am a bit unsure. We don't want to use Kubernetes for SQL, so the current idea is to go for Google Cloud SQL managed service (Are the competitors better for blue/green deployment of SQL?). The question is can it sync the data between old and new versions of the database nodes?
Let's say that we have 3 active Pods and at least 2 active database nodes (and a load balancer).
So the standard deployment should look like this:
Pod with the new code is created.
New database node is created with current data.
The new Pod gets new environment variables to connect to the new database.
Database migrations are run on the new database node.
Health check for the new Pod is run, if it passes Pod starts to receive traffic.
One of the old Pods is taken offline.
It should keep doing this iteration until all of the Pods and Database nodes are replaced.
The question is can this work with the database? Let's imagine there is a user on the website that is using the last OLD database node to write some data and when switched to the NEW database node the data are simply not there until the last database node is upgraded. Can they be synced behind the scenes? Does Google Cloud SQL managed service provide that?
Or is there a completely different and better solution to this problem?
Thank you!
I'm not 100% sure if this is what you are looking for, but for my understanding, Cloud SQL replicas would be a better solution. You can have read replicas [1], that are a copy of the master instance and have different options [2]
A read replica is a copy of the master that reflects changes to the master instance in almost real time. You create a replica to offload read requests or analytics traffic from the master. You can create multiple read replicas for a single master instance.
or a failover replica [3], that in case the master goes down, the data continue to be available there.
If an instance configured for high availability experiences an outage or becomes unresponsive, Cloud SQL automatically fails over to the failover replica, and your data continues to be available to clients. This is called a failover.
You can combine those if you need.
Is there any reliable backup & restore method, tool, ... for Redis DB ?
been googling around couples of hours and there was nothing just copy the dump file /var/lib/redis/dump.rdb or some scripts that uses MIGRATE (idk if this even count as backup)
Ok lets say there is Redis DB (big one) and its Windows version of Redis
github.com/MicrosoftArchive/redis
so we need a copy of this DB in other branch of company that uses final Linux version of Redis, cuz windows version is outdated and its performance is not good as Linux version.
all keys and values are encrypted and stored as binary format in Redis, so is there any reliable backup & restore for Redis DB ?
There are solutions around that helps you automate this process.
Making a Redis backup is quite simple though:
Review / update your Redis configuration.
Create a snapshot for your Redis data (known as a "dump"/"rdb file").
Save the RDB file to a remote location
To create the snapshot (2) you'll need to use redis-cli SAVEor BGSAVEcommand.
You'll then need to create a little script (you can find one here) to transfer your .rdb file to a remote storage (like AWS S3).
You can then automate all of that using CRON.
Of course, you can now use services like SimpleBackups to get all of that done for you.
I am currently using Unison across 2 computers (server and laptop). I need to create another connection where I can timely backup my data from server.
laptop <--> server -> backup
Here the connection to backup from server can be unidirectional. Is there any way to accomplish this?
This is a very common thing to do. When setting up Unison across multiple machines, you should prefer a star topology. So if you can, you should run another instance of Unison, along with any backup-related scrips, on your machine where you are storing your backups. It should look about the same as your setup on your laptop (depending on where your backups are being stored).
Using Vagrant+Chef Solo I'm setting up two VMs: #1 is a TeamCity server, #2 is a TeamCity agent. Provisioning is done by first installing the TeamCity server package on VM #1, then the agent VM is booted and requests data from the server which is used to install the agent. That whole thing works fine.
But now I want to alter the server after the agent is done provisioning. I want to modify the server's database directly, to change an attribute that is only available after the agent has spun up. But is there a way for one VM's provisioning to trigger another VM? Once the agent is done I'd like to somehow resume provisioning the server, so I can make the database edit..
Any thoughts, recommendations, or feedback welcomed. I'm new to Vagrant, Chef, and TeamCity, so there's a chance I'm missing a much easier solution.
* Why do I want to edit the DB directly you may be wondering? TeamCity agents must be authorized before they can be used, and I want to do this programmatically. The solution I've found is to directly edit the DB, because authorization functionality is not exposed via the TeamCity REST API (as far as I can tell)
If you can test the agent is installed/answering, you may add a ruby block looping over this test before continuing the recipe execution.
This loop should have a sleep and a counter to avoid infinite loops.
I've no knowledge of teamcity, so can't tell if it's the best way.
In general, Chef is designed to manage your system, not simply provision it (though this is less true in the modern Cloud world with "golden image" strategies). Nonetheless, in your case, you best bet is to just setup chef-client as a service that runs every 15 minutes. Once the client has finished provisioning, the next run of the server will be able to authorize it.
If you really want to "trigger" the one from the other, you'd need either do that externally with something like etcd or consul, or you would need to setup an ssh keypair between the boxes and add a ruby_block on the client that either does the database modification directly, or calls chef-client on the server.
We have a number of web-apps running on IIS 6 in a cluster of machines. One of those machines is also a state server for the cluster. We do not use sticky IP's.
When we need to take down the state server machine this requires the entire cluster to be offline for a few minutes while it's switched from one machine to another.
Is there a way to switch a state server from one machine to another with zero downtime?
You could use Velocity, which is a distributed caching technology from Microsoft. You would install the cache on two or more servers. Then you would configure your web app to store session data in the Velocity cache. If you needed to reboot one of your servers, the entire state for your cluster would still be available.
You could use the SQL server option to store state. I've used this in the past and it works well as long as the ASPState table it creates is in memory. I don't know how well it would scale as an on-disk table.
If SQL server is not an option for whatever reason, you could use your load balancer to create a virtual IP for your state server and point it at the new state server when you need to change. There'd be no downtime, but people who are on your site at the time would lose their session state. I don't know what you're using for load balancing, so I don't know how difficult this would be in your environment.