I was asked to implement a High Availability and auto-failover in postgresql and I have been searching the internet all over to find the right architecture for that.
I have tried to do it in two architectures:
RedHat cluster
UCARP
Both ways came out pretty bad when I've meet bugs on UCARP restarting as master-master after several reboots and Redhat cluster fails to manage properly PostgreSQL service.
I would like to ask if anyone has ever succeeded to implement such an architecture and would like to explain me how or refer me to a tutorial that actually works.
The components that I have are: PostgreSQL at latest version (9.4), RHEL 6.6 and higher, all on virtual machines.
Thanks in advance,
Aviel Buskila.
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I have a FreeBSD 12.1-RELEASE server and a CentOS 7 server. Both run on amd64.
I would like to set up a cluster file system, that runs on both platforms well. It should have CentOS 7 packages and FreeBSD packages. The solutions should be open-source software and "free of use".
After a little research, I found the following, but nontheless I always encountered drawbacks:
MooseFS3: Works on FreeBSD and CentOS, has packages for both, but only the MooseFS3 Pro version, which is commercial, has the functionality of real cluster functionality such as the possibility of mounting the file system from several nodes. Also I had locking problems with files that where access by my dovecot imap server daemon, when I run dovecot from the file system.
GlusterFS: Seems to work well, but there are no packages for the most current version of 8.x for FreeBSD. FreeBSD provides only a port for GlusterFS 3.x as of today. Different versions of GlusterFS can not operate together.
Ceph: Is very complex to configure, and I couldn't execute all of the steps of the official FreeBSD documentation for it, since the tool ceph-disk is deprecated in favor of ceph-volume. With Ceph-volume, though, I could not get it running with my zfs pool on FreeBSD, since the plugin for zfs for ceph-volume seemed to have some Linux code in it when it was ported to FreeBSD or similiar, so it might only run with ZFSOnLinux on Linux itsself.
OCFS2: I don't have much experience with that one, but its releases seem a bit outdated.
Lustre: No packages for FreeBSD and no acurate and up-to-date documentation how to set it up on a recent FreeBSD system
BeeGFS (Fraunhofer): No packages for FreeBSD, only for Linux
Hadoop MapR filesystem: Has a use case more for BigData storage than for a UNIX cluster filesystem, I don't know if it has FreeBSD packages.
So I don't find a good solution for a Cluster filesystem that runs on both FreeBSD and CentOS Linux. Even I'm planning to migrate the CentOS server to Fedora Server, so it should run there as well.
Anyone who can recommend me a recent compatible cluster file system that I could use on both FreeBSD and CentOS/Fedora Server and that allows real cluster file system features like replication and HA?
Or is there currently no cluster filesystem that fulfills my needs and I have to migrate the two machines running the same OS?
Thank you in advance.
Best regards,
rforberger
MooseFS3: Works on FreeBSD and CentOS, has packages for both, but only the MooseFS3 Pro version, which is commercial, has the functionality of real cluster functionality such as the possibility of mounting the file system from several nodes.
This is not true, you can mount MooseFS Community from as many nodes as you wish.
Glusterfs may be worth to try, it is based on fuse, which is available on FreeBSD, so you need only to build the userspace part, which may not be impossible, if it is not available for you OS version. On Linux it is definitely the simplest one to set up, since it comes packaged with most of the distros.
Lustre, despite supporting replicated directories, is more of a parallel filesystem oriented to HPC and high I/O performances, than a clustered filesystem oriented at redundancy, so I would not even consider it if redundancy is your purpose.
I have no experience with the other ones.
I'm looking for the minimum "hardware" requirements for a virtual machine to set up an OpenLDAP server.
I only found software documentation about this, but there is none about hardware, except that it requieres very little requirements.
Has someone did some research on this topic, or has any data or examples of actual OpenLDAP implementations?
I'm planning on using a Linux CentOS as OS.
I am a newbie to Xen and want to download it on my machine which currently has CentOS7. I have been researching and experimenting for a couple of days but can't seem to find a straightforward answer on how to install a fully functioning Xen on CentOS7. I tried using the workaround at http://www.lairdscomputer.com/Blog/tabid/62/EntryId/74/Installing-Xen-4-on-Centos-7.aspx, but it seems that some of the packages it uses might be outdated.
Is it even possible to install Xen on CentOS7, even if it is missing some parts to it? Would it be better just to go back to CentOS6.x so that I can install Xen4CentOS?
Thanks in advance! Any advice is appreciated!
Afaik RedHat therefore CentOS is not supporting Xen whoever in fact it is possible.
I am using xen4centos on my Centos7 server, it was installed along with official article from wiki:
https://wiki.centos.org/HowTos/Xen/Xen4QuickStart
It it is not, please provide some logs, errors etc
This question might be slightly subjective, but I am unsure where else it would be better suited.
I have used Orchard on a number of projects where the server was Windows Server based - integrating with AD, SQL etc to provide a MVC based portal - like stealing candy from a toddler!
I have been exploring MonoTouch recently, and installed Orchard on OSX under ModMono as per http://docs.orchardproject.net/Documentation/Running-Orchard-on-Mono.
It all seems to run fine, and fast, but I am unsure whether to back this on a commercial venture. I have always used MySQL or MSSQL as the DB, whereas my current install is running PostgreSQL - something new (which is always good).
Does anyone know of any sites which use Orchard running on Mono, with ModMono (Apache2) and PostgreSQL?
I plan to deploy to a cloud server running CentOS and Mono to do further testing before going any further, but think it could be an exciting avenue to explore.
I can't say I know of any sites that run Orchard on Mono commercially but I do know of a lot of sites that use Mono, Postgresql and CentOS. But if it works on a Mac running Modmono and Postgresql then it should work on CentOS.
The only issues that you may face running on Linux is case sensitivity. If you do run in to case sensitivity issues when you are trying out Orchard on Linux then you may want to configure your site to use Mono IOMAP temporarily until you fix an issues with case sensitivity.
This is a very reliable and cost effective stack. It may take a bit of research and problem solving to get up and running initially but once it's running it should be very stable.
I am currently near the end of porting an application that is going to be using Mono, Postgresql and Ubuntu running on Amazon EC2. I believe that Ubuntu is better than CentOS when it comes to Mono as it is much easier to setup and seems to be better supported. You can use the badgerports repositories located here if you want to try out the latest version of Mono on Ubuntu.
I'm currently testing Memcached in a Windows machine and we are planning to use it in production while Microsoft Velocity is still in CTP. It is running well so I believe that Memcached for Windows will do well when our site is already in production. I'm reading some blogs pertaining to this issue and some of them just mentioned that it must not yet be used in production.
If there are issues, please tell why? And please, if you have any links about this matter, just post it here. Thanks.
There is no official release of memcached on Windows. We're working on it right now, but unless you're pulling from a dev branch or you've downloaded a pre-release, you've definitely got an unsupported version with a large number of bugs and missing features from the last couple of years.
I've been using memcached in production for several years now (since early 2008). We're currently using a 12-instance cluster and it absolutely hums. I would recommend memcached any day of the week.