I am a little confused on how to setup a one way 3 tier replication using symmetricds.
What I am trying to setup is something like this:
The company server is not connected to the internet and as you can see it's one way, and basically the final tier is a readonly database used by a web application .
How to setup this 2 steps replication?
Do I need to install Symmetric (java . etc) in each server?
Need some guideline here, thanks.
Zack,
It sounds like at a minimum you would want 2 SymmetricDS installations. One for your company server and intermediate server. If these are on the same local network a multi-homed (local node) setup would work. I would make the company server the master node and the intermediate a local node in the same installation. The final installation of SymmetricDS would be close to your DB internet server (you want a reliable JDBC connection here). Then I would setup 3 node groups (ex: server, intermediate, web). I would build group links:
intermediate pulls from server (for your data)
intermediate pushes to server (for heartbeats and config)
intermediate pushes to web (for your data and allows you to keep a firewall in place from outside connections in).
intermediate pulls from web (for heartbeats and config)
From here you can select your tables for replication and should be all set.
Take a look at the demo here to become more familiar with the basic configuration.
Start off by syncing your company and intermediate server.
Once you are syncing your company and intermediate server, add your third tier. Additional information on adding multiple tiers can be found here.
SymmetricDS uses JDBC drivers to communicate with the database. JDBC is not intended to run over the internet. This is why SymmetricDS should be installed local to each DB instance.
It is possible to point one SymmetricDS instance to two different DB's. You should only do this if both DBs exist on the same network. More information on adding multiple nodes here.
Related
I want to create a weblogic cluster that has two managed servers each running on a physically separated remote machine
According to weblogic docs
All Managed Servers in a cluster must reside in the same domain; you
cannot split a cluster over multiple domains.
Ref: https://docs.oracle.com/cd/E24329_01/web.1211/e24970/understand_domains.htm#DOMCF125
If this is the case then where am I suppose to create the Managed Server on the remote machine. Since the managed server can only be created in the domain, am I not suppose to create the domain on the remote machine for holding managed server?
[edit]
As per the below documentation
https://docs.oracle.com/cd/E17904_01/web.1111/e14144/tasks.htm#WLDPU136
It seems that the admin server domain is replicated on remote managed servers using pack and unpack commands.
That means a separate copy of domain must be made available on remote machines in order to operate managed servers on it.
Is it the fault with the oracle documentation-
Because then its the violation of the Domain Restrictions rule which says that there should be only one domain per cluster?
Domain is logical group for all Weblogic resources like relam, cluster, manged servers. You can create managed servers on physically separated remote machine and group them in a same Weblogic domain.
In a WebLogic Server domain there is always one administration server. This special instance of WebLogic Server is responsible for the configuration of the entire domain. Other servers in the domain are called managed servers. These are typically the servers on which you run your applications. A domain can contain any number of managed servers. You can find the detail on this link -
https://docs.oracle.com/cd/E17904_01/web.1111/e14144/tasks.htm#WLDPU136
I have a System which has application server and database server.
In the initial stage, both Database and Application Servers run in a same Physical Server. After that we have segregated these two servers in to separate segments in the network. i.e We have defined two separate VLAN s as application and database and put these two servers in to these two different vlans and given the required access permission through the firewall.
After the segregation we had a major issue regarding the slowness between application and db servers. We have checked the network connectivity and we couldn't find any issue from the network side for the slowness.
After that we have put both Application and DB servers in to one server like the implementation stage. Then the slowness issue has rectified.
I want to know what could be happen for this slowness.
Please advice me.
Thank you
We have a staging and production SharePoint farm housed within Windows Azure. All servers run Windows Server 2012. We're having the same issues in both environments, but for this question, I'll focus on the staging environment.
For the staging environment, I have several servers within the SharePoint farm and 2 SQL servers. All servers are located on the same subnet and affinity group. There is a DHCP server that hands out 192.168.X.X addresses for all servers on the subnet.
I've created a WSFC with both SQL servers as nodes. I've tried creating the cluster with an IP of an unused DHCP address (192.168.X.X) and with a link local address (using a PowerShell script to create the cluster found online from Microsoft). In both cases, the cluster IP is not accessible from any machine on the subnet. However, in both cases, the cluster appears to be up and restarting the active node pushes the passive node to the new active node. I think that this may be one of my root problems.
My final goal is to create an SQL Availability Group Listener for SharePoint to use for DB connections. With the cluster created, I am able to create an Availability Group in SQL Management Studio. I can see that it works: when rebooting the primary replica, the secondary turns to primary, all DBs are synced and up to date, etc. However, when I try to create the AG Listener, it fails with an error claiming that it cannot access the cluster or the cluster is not active.
I've read a lot online. Some claim that it's not possible to create AGs in Azure, others claim that this hotfix fixes things (http://support.microsoft.com/kb/2854082), and a few that claim it works when you set the Listener IP to the public endpoint. I've tried them all and haven't had any success. There's got to be some way to increase the reliability of SQL in a totally enclosed, Azure environment. Does anyone have any experience with this? Has anyone gotten it to work? If so, how did you do it? If not, is there another way to go about SQL availability?
I have multiple content servers on different machines. I need to check the status of every server. I'm concerned about things like disk size, priority etc.
One solution that I'm using now is to install a Window Service on each machine which regularly checks the server but I have to manually install the service on each server.
Is there any way I can get the server information like disk space from a WCF service or using a windows application? I want to create a single watcher for my servers as I have to add servers sometimes.
Look at windows WMI you can make remote calls to machines so long as you have permissions to do so. You will only have to run one service on one server that can connect to the others.
http://msdn.microsoft.com/en-us/library/windows/desktop/aa394582(v=vs.85).aspx
How can I work with Novell eDirectory services in J2SE? Will JNDI work with eDirectory? What are some resources I can use to learn about whatever library or libraries you suggest?
I just want to play around with retrieving information via LDAP for right now, and if I get things working the way I want, I will probably need to be able to modify objects later on.
Thanks!
JNDI should work with eDirectory.....
try; http://developer.novell.com/wiki/index.php/Jldap and http://developer.novell.com/wiki/index.php/Novell_LDAP_Extended_Library
Used it successfully with OpenLDAP and should suffice for eDirectory as well.
Any LDAP interface you want to use should work fine against eDirectory.
Be aware that the configuration of the LDAP server may not allow clear text passwords, thus a bind to port 636 via SSL (Where you have the certificate imported into the keystore already) or via TLS (retrieve the tree CA's public key on the fly).
If you have administrative access to the eDirectory server, you can easily change that, but still best to confirm that you can get it to work over SSL/TLS (aka LDAPS).
If you really need it, you can ask the admins for a server with only a replica of some test partition (and thus no real user data in its view) and test via cleartext against that.
It is very easy in eDirectory to add a new replica of a partition, carve off or merge a partition, and all can be done live.
It is similarly very easy to host replicas of many partitions on one server. (The official limit is, no limit on the number or partitions in a tree, or replicas on a server, but it used to be 256 in older versions (before 8.x) )
If you are allowed access to the eDirectory server, you want to to ask for access to Dstrace (several versions of this, see Many Faces of Dstrace). There is a web interface (server:8008 on Netware, 8010 on Windows, 8028 on Unix/Linux usually) or other interfaces. If you enable the LDAP trace option (and turn off all the others) you can fairly completely debug what is going on at the server side. See the errors, the communication, or lack thereof and so on.