For our customer the application which is running is using MySQL database. However, this server is without monitoring. I want to install OpenNMS (which uses PostgreSQL) application to monitor the solution and send the traps to main NMS system.
Is there any problem having both on the same server?
No, there is no technical problem. Both default to different ports they listen on.
The only problem that could arise is that each individual DB might be slower compared to an installation on separate phyiscal machines because they are both share (and fight for) for the same resources (I/O, memory, CPU, network, ...)
Related
I am working in a project where we are using Go as a web server and MySQL.
We have been told to implement fault tolerance to handle a hardware crash. We were given 2 servers which have MySQL and the Go-server on them.
We have succesfully set up replication in MySQL, but we are struggling with the failover part. Our thought was to get an extra server with HAProxy to have a primary server and then being able to failover to the backup server.
We also considered using MySQL failover, but did not see how we could redirect the traffic using it.
Is this a reasonable plan? Or what would you recommend that we do instead?
If you want two identical servers connecting to their local MySQL instances, you need a way of deciding which one is the production server. There are a number of solutions for that, including
Setting up a reverse proxy, as you mention, but then, your proxy
itself becomes a SPOF,
Using a floating IP, also known as a failover
IP, but this only works if your host supports it. Cloud providers
typically support them, as well as some bare metal server providers.
There is nothing specific to Go as far as I know.
From what I gather, the only way to use a MySQL database with Azure websites is to use Cleardb but can I install MySQL on VMs provided in Azure Cloud Services. And if so how?
This question might get closed and moved to ServerFault (where it really belongs). That said: ClearDB provides MySQL-as-a-Service in Azure. It has nothing to do with what you can install in your own Virtual Machines. You can absolutely do a VM-based MySQL install (or any other database engine that you can install on Linux or Windows). In fact, the Azure portal even has a tutorial for a MySQL installation on OpenSUSE.
If you're referring to installing in web/worker roles: This simply isn't a good fit for database engines, due to:
the need to completely script/automate the install with zero interaction (which might take a long time). This includes all necessary software being downloaded/installed to the vm images every time a new instance is spun up.
the likely inability for a database cluster to cope with arbitrary scale-out (the typical use case for web/worker roles). Database clusters may or may not work well when a scale-out occurs (adding an additional vm). Same thing when scaling in (removing a vm).
less-optimal attached-storage configuration
inability to use Linux VMs
So, assuming you're still ok with Virtual Machines (vs stateless Cloud Service vm's): You'll need to carefully plan your deployment, with decisions such as:
Distro (Ubuntu, CentOS, etc). Azure-supported Linux distro list here
Selecting proper VM size (the DS series provide SSD attached disk support; the G series scale to 448GB RAM)
Azure Storage attached disks being non-Premium or Premium (premium disks are SSD-backed, durable disks scaling to 1TB/5000 IOPS per disk, up to 32 disks per VM depending on VM size)
Virtual network configuration (for multi-node cluster)
Accessibility of database cluster (whether your app is in the vnet or accesses it through a public endpoint; and if the latter, setting up ACL's)
Backup / HA / DR planning
Someone else mentioned using a pre-built VM image from VM Depot. Just realize that, if you go that route, you're relying on someone else to configure the database engine install for you. This may or may not be optimal for what you're trying to achieve. And the images may or may not be up-to-date with the latest versions, patches, etc.
Of course, what I wrote applies to any database engine you install in your own virtual machines, where a service provider (such as ClearDB) tends to take care of most of these things for you.
If you are talking about standard VMs then you can use a pre-built images on VMDepot for that.
If you are talking about web or worker roles (PaaS) I wouldn't recommend it, but if you really want to you could. You would need to fully script the install of the solution on the host. The only downside (and it's a big one) you would have would be the that the host will be moved to a new host at some point which would mean your MySQL data files would be lost - if you backed up frequently and were happy to lose some data then this option may work for you.
I think, that the main question is "what You want to achieve?". As I see, You want to use PaaS solution with Web Apps or Cloud Service and You need a MySQL database. If Yes, You have two options (both technically as David Makogon said). First one is to deploy Your own (one) server with MySQL and connect to it from the outside (internet side). Second solution is to create one MySQL server or cluster and connect Your application internally in Azure virtual network. WIth Cloud Service it is simple but with Web App it is not. You must create VPN gateway in Azure VM and connect Your Web App to this gateway. In this way You will have internal connection wfrom Your application to Your own MySQL cluster.
I have done extensive research, i feel that i have good candidates but i still lack enough knowledge to decide which one i should implement, ideally i would like to hear from someone that actually implemented a solution to a similar problem.
The Problem
Our project consists of a community of distributed nodes (25 nodes). The nods run on Linux computers, and are installed in the typical residential setting (behind a NAT), with wide dispersion geographically and ISP wise.
Our software on the node collects a variety of its own unique data which is logged to MySQL DB on the local host (node) which is not WAN accessible directly. We also have a Web interface for each node that uses the local node DB to allow the local node user to visualize certain data and parameters; this is only accessible on the LAN.
We typically set-up and maintain an open port for SSH from our labs to each node. All remote DB on nodes have the exact same schema but completely different data. We need an automated way to collect all data from all the nodes and get them to our WAN accessible lab servers (Windows 7 servers, but can be Linux if it provide a better solution). We have narrowed the option as follow:
Solutions:
Create a .bat script that sequentially connect to each node over SSH to import data.
Use the web interface that runs on each node to periodically query the local db then save that data to a central MySQL server. I know i can connect to two db in PHP. seems to be doable here.
Use the MySQL supported “slave-master” replication setup which will duplicate all remote databases on the server.
Use the MySQL supported federated engine setup which will link local tables to remote ones.
Questions:
Are all these viable solutions?
Any major cons i should be aware of for the viable ones?
is there better solutions available (paid or otherwise) ?
Simple question can a Java service layer running on Tomcat7 on a host machine connect to persistent data store (mySQL) running inside a virtual box with portforwarding? I want to know if the hibernate or Jdbc connection strings from host machine work if mySQL server is installed inside a VirtualBox.
Also if it does work can I expect behavioral deviations in terms of speed and connection pooling if everything is packaged into one single system and deployed in a real world web server in a single enviroment?
The short answer is yes, it is possible and will work. You will likely have to play with the firewall settings on your virtual box instance. You don't specify OS, so it's hard to tell you what exactly you'll need to tweak.
As far as deploying this in a real-world environment, if you mean production, you probably should NOT do that. This is a great setup to build on, but not something I would run in production.
To be clear, there won't be any issues behaviorally speaking, it will act as MySQL always acts, but it will absolutely be slower than running it on 'bare metal' -- how much slower will vary based on hardware, workload, etc. and it is generally not a great design for a production deployment..
Is there an easy way to setup an environment on one machine (or a VM) with MySQL replication? I would like to put together a proof of concept of MySQL replication with one Master write instance and two slave instances for reads.
I can see doing it across 2 or 3 VMs running on my computer, but that would really bog down my system. I'd rather have everything running on the same VM. What's the best way to proof out scalability solutions like this in a local dev environment?
Thanks for your help,
Dave
I think to truly test MySQL Replication it is important to do so in realistic constraints.
If you put all the replicate nodes under one operating system then you no longer have the bandwidth constraint, the data transfer speed would be much higher that what you would get if those replicate DBs are on different sites.
Everything under one VM is a shortcut to configurations, for instance it does not make you go through the configuration of the networking.
I suggest you use multiple VMs, even if you have to put them under one physical machine, you can always configure the hypervisor to make the packets go through a router, in which case the I/O will be bound by whatever the network interface has as throughput.
I can see doing it across 2 or 3 VMs
running on my computer, but that would
really bog down my system.
You can try and make a few VMs with JeOS (Just Enough OS) versions of the operating system you want. I know Ubuntu has one and it can boot on 128 RAM, which makes it convenient to deploy lots of cloned VMs under one physical machine without monster RAM.
Next step would be doing the same thing on a cloud (Infrastructure as a Service, IaaS) provider, and try your setup on different geographical sites.
If what you're testing is machine-to-machine replication, then setting up multiple VMs on a virtual private network would be the correct environment to test it. If you use Ubuntu Server, you don't have to install more than you actually need -- just give the VMs enough space for a base install + MySQL + your data. Memory usage can be as little as 256MB per VM. All you have to do is suspend or shutdown the VMs when you're not running a full-up test.
I've had situations where I was running 4 or more VMs simultaneously on my workstation, either for development or testing purposes -- it's not that taxing unless you're trying to do video rendering in each VM.