I have setup symfony mysql site with mysql master slave configuration. How ever while testing with jmeter I observed that almost all load is going to master and 1-2% to the server.
Referred how to use master-slave but couldn't help. Is there any specific parameter to influence Server to pick slave connection?
PS- I am performing all read operations only
Doctrine will use the master for all queries after any kind of update.
You can tell doctrine to switch back to a slave after inserts/updates:
$em->flush();
$em->getConnection()->connect('slave');
You could also check whether you have a request listener doing inserts/updates, and apply that fix.
Related
Is it possible to configure a read-only server that remains slave even though no more masters are available with MariaDB Maxscale 6.
I tried it with a readconroute router, but that one turned the slave eventually in to a master as well.
/Theo
If you are using the mariadbmon monitor, you can use the servers_no_promotion parameter to list the server you want to remain read-only.
For galeramon there should be no need to keep servers as read-only as all functioning nodes are capable of receiving writes.
I'm migrating salt to salt multimaster.
So in minions config I have my master list, with some multimaster parameters.
I see each master have his connected minions and can talk only with its.
I actually have jobs which send salt commands to my master to run tasks on some minions.
With multimaster I will need to connect on each master and run command if I want to reach all desired minions.
Is there a way to run commands to all minions from only one host ?
You can use syndics and have another master on top.
https://docs.saltstack.com/en/latest/topics/topology/syndic.html#syndic
this way the minion will connect to your normal Master/s where Syndic/s is also installed and can failover to any of them. Syndic/s (another form of a special minion) will connect to MoM (Master of Masters) and you can push commands to all your masters. You can also have multiple MoMs which syndic/s are always connected to.
This offers HA for your minions, masters/syndics and masters of masters.
It has some performance impact if you plan to deploy a large number of minions and might require tuning many options.
Unfortunately the Syndic architecture is not officially supported by Saltstack the time that I'm writing this but they welcome community patches. The main reason is because they provide HA through their Enterprise product and want customers purchasing the HA option rather than getting it for free.
The latest is just my personal opinion based on PRs/Feature Requests I have seen being rejected or dismissed to be developed by the Saltstack team. I don't think they made any official announcement about this.
My setup is as the following:
MaxScale 2.1.4 -> Master -> 2 slaves (both MariaDB 10.2). *CentOS 7
Most of my queries are prepared statements so the master basically handles 90% of the queries right now.
I've enabled the hintfilter and tried to add a hint to a query:
/* maxscale route to server server2 */
Unfortunately, it still ends up on the master.
I understood that MaxScale 2.2 should introduce some auto solution for prepared statements. However, I need some temp solution(I'll try to look into ProxySQL if none is found).
Any help would be highly appreciated.
If you used the mysql command line client to test it, remember to enable SQL comments by using the -c flag.
Since MaxScale 2.0.1, the hint mechanism will override any decisions taken by the router itself if the router supports hints. The readwritesplit and schemarouter routers are currently the only routers that support routing hints so make sure you are using one of these routers.
Node.JS seems limited in its ability to live-update code and in its ability to automatically isolate exceptions. Both of which are practically by default in Java.
One very effective way to live-update is to have a listener process that simply echos communication to/from the child process. Then to update, the listener starts up a new child (which reads the updated code automatically) and then starts sending requests to the new child,, ending the old child when all requests are complete.
Is there already a system that provides this http functionality through stdout/stdin.
Is there a system that provides TCP server or UDP server functionaility through stdout/stdin.
By this I mean, providing a module that looks like the http or net module with the exception that it uses stdout/stdin for the underlying I/O.
Similar to This CGI module
some applications will only have to change require('http') to require('cgi')
I intend to do something similar. I hope to re-use code if it is already out there, and also to easily convert a small or single purpose webserver, into this listener layer which runs many webapps. It is important that cleanup occurs properly. Connections that end or error should be freed up and the end/error events/commands should be properly echoed both ways.
(I believe a common way is to have the children listen on ports and the parent communicate with those ports, but I think an stdout/stdin solution will be more efficient)
Use nginx (HttpUpstreamModule) or HAProxy. In both cases you'd run them in front and mark a backend as down and then bring it back up when you need to do a live upgrade.
I'm not certain that this is what you're looking for (indeed, I'm not certain that I understand your question), but Remy Sharp has written a very helpful node module called nodemon. It promises to "monitor for any changes in your node.js application and automatically restart the server." This may help with the issue of live updating code.
We currently have an ASP.NET Web Application running on a single server. That server is about to hit the danger zone regarding CPU usage, and we want to deploy a second server.
What would be the best way to handle Session State?
We currently run InProc. But that's not an option with 2+ servers, as we want to exclude a single server from the WLB rotation sometimes to do maintenance work. Even though we use sticky load balancing, we would have to wait for all users to exit before we can exclude the server from the WLB rotation.
So I was looking at this MSDN page: http://msdn.microsoft.com/en-us/library/ms178586(VS.80).aspx
I guess my main question is: If we use the State Server mode. Can we ensure rendudancy by deploying the state server across two servers? To avoid having a single point of failure.
If you want one of the standard options I'd use SQL Server in a failover cluster. BTW have you consider memcacheddb?
Sql State server would be a better option: This link might help Sql State Server
. I don't believe you can run state server across multiple machines.
Use either Scale Out State server (faster better) or SQL State (slower simpler). But beware if you store any none serializable objects into Session state, because you'll get exceptions after migration.
you might want to look into project velocity (http://msdn.microsoft.com/en-us/data/cc655792.aspx) . It has limited support now because it is on CTP3 but later this year it would be RTM. I highly suggest you watch the MIX09 session about it here
I would suggest looking into p2p Session State Server - link is here: http://www.codeproject.com/KB/aspnet/p2pstateserver.aspx
Worked for me. The only drawback is that if you have a large data set it was taking forever to replicate between peers.