I am going to use redis as the web cache for geoserver, so I need to understand the database connection in geoserver. I have imported geoserver in Eclipse, and there are two projects named gs-sec-jdbc and gs-web-sec-jdbc. I do not know what the “sec" means and what are the differences between these two projects. Any help or tutorial is appreciated！ Thank you !
These two modules are part of the security subsystem (gs-web-sec-jdbc is the web based user interface). They are almost certainly not the modules you are looking for.
If you intend to use redis to store WMS output images then you need to look at how GeoWebCache works.
If you want to provide a cache between GeoServer and a JDBC database then you will need to explore GeoTools' JDBC datastore mechanism.
Related
We are using prometheus in our production envirment recently. Before we only have 30-40 nodes for each service and those servers not change very often, so we just write it in the prometheus.yml, but right now it become too long to hold in one file and change much frequently then before, so my question is should i use file_sd_config to put those server list out of yml file and change those config files sepearately, or using consul for service discovery(same much easy to handle changes).
I have install 3 nodes consul cluster in data center and as i can see if i change to use consul to slove this problem , i also need to install consul client in each server(node) and define its services info. Is that correct? or does anyone have good advise.
Thanks
I totally advocate the use of a service discovery system. It may be a bit hard to deploy at first but surely it will worth it in the future.
That said, Prometheus comes with a lot of service discovery integrations. It's possible that you don't need a Consul cluster. If your servers are in a cloud provider like AWS, GCP, Azure, Openstack, etc, prometheus are able to autodiscover the instances.
If you keep running with Consul, the answer is yes, the agent must be running in every node. You can also register services and nodes via API but it's easier to deploy the agent.
I was wondering about how deepstream decides to store an info in cache vs database if both of them are configured. Can this be decided by the clients?
Also, when using redis will it provide both cache and database functionality? I would be using amazon elastic cache with redis backend for the same.
It stores it in both, first in the cache in a blocking way and outside the critical path in the database in a non-blocking way.
Here's an animation illustrating this.
You can also find more information here: https://deepstream.io/tutorials/core/storing-data/
Why do Apache Hive needs Apache Thrift? On the Thrift's site it says that it can compile in multiple languages, but I can't understand where does it fits and why do Hive need it.
Thanks
Cited from safaribooksonline:
Chapter 16. Hive Thrift Service
Hive has an optional component known as HiveServer or HiveThrift that
allows access to Hive over a single port. Thrift is a software
framework for scalable cross-language services development. See
http://thrift.apache.org/ for more details. Thrift allows clients
using languages including Java, C++, Ruby, and many others, to
programmatically access Hive remotely.
The CLI is the most common way to access Hive. However, the design of
the CLI can make it difficult to use programmatically. The CLI is a
fat client; it requires a local copy of all the Hive components and
configuration as well as a copy of a Hadoop client and its
configuration. Additionally, it works as an HDFS client, a MapReduce
client, and a JDBC client (to access the metastore). Even with the
proper client installation, having all of the correct network access
can be difficult, especially across subnets or datacenters.
Couldn't have said it better. Emphasis mine.
https://cwiki.apache.org/confluence/display/Hive/HiveServer
HiveServer is an optional service that allows a remote client to submit requests to Hive, using a variety of programming languages, and retrieve results. HiveServer is built on Apache ThriftTM (http://thrift.apache.org/), therefore it is sometimes called the Thrift server although this can lead to confusion because a newer service named HiveServer2 is also built on Thrift.
For more details on how to connect to hive server(thrift server) see the link above.
i use sesame for a project and i use a local nativestore file repository. everything is fine but when multiple clients use my application silmuntaneusly the repository locks.How can i deal with parallel connections problem;
A Sesame Native Store assumes it has sole, unique access to its datadir. This means that you can not create two NativeStore objects that use the same datadir, as this will cause inconsistencies and potential deadlocks. So, you need to share a single NativeStore object.
In a single JRE, this can be easily achieved by using a RepositoryManager. See this article for an explanation and code examples. If your setup requires several independent client applications to connect to Sesame, you will either have to implement your own server app for these clients to connect to, or you can use a Sesame Server and have each client connect via a HTTPRepository.
I am working on a project which has following requirements:
Perform sticky based load balancing(based on SOAP session ID) onto multiple backend servers.
Possibility to plugin my own custom based load balancer.
Easy to write and deploy.
A central configuration file(Possibly an XML), to take care of all the backend servers.
Easy extraction of a node from this configuration file(Possibly with xpath).
I tried working with camel for a while but, wasn't able to do perform certain task with it.
So thought of giving a try to Akka.
Will akka be possibly able to satisfy the above requirements?
If so is there a load balancing example in akka or proxy example?
Would really appreciate some feedbacks.
You can do everything you've described with Akka.
You don't mention what language you're working with, Scala or Java. I've included links to the Scala documentation.
Before you do anything with Akka you HAVE TO read the documentation and understand how Akka works.
http://doc.akka.io/docs/akka/2.0.3/
Doing so, you'll find Akka is perfect for the project you've described with some minor caveats.
Once you read the documentation the following answers should make a lot of sense.
Perform sticky based load balancing(based on SOAP session ID) onto multiple backend servers.
Load balancing is already part of the framework (it's called Routing in Akka http://doc.akka.io/docs/akka/2.0.3/scala/routing.html) and Remoting (http://doc.akka.io/docs/akka/2.0.3/scala/remoting.html) will take care of the backend servers. You can easily combine the two.
To my knowledge the idea of sticky load balancing is not a part of Akka but I can envision this being accomplished with a Map using the session ID as the key and the Actor name (or path) as the value. A quick actorFor will take care of the rest. Not well thought out but should give you a good idea of where to start.
Possibility to plugin my own custom based load balancer.
Refer to the Routing documentation.
Easy to write and deploy.
This depends on your aptitude and effort but after you read certain parts of the documentation you should be build a proof of concept in a couple of hours.
Deployment can be a bit frustrating mostly because the documentation isn't really great with respect to deploying Akka networks with remote components. However, there are enough examples on the web that you can figure out how to get it done...eventually. Once you do it once it's no big deal.
A central configuration file(Possibly an XML), to take care of all the backend servers.
Akka uses Typesafe Config (https://github.com/typesafehub/config) which is a lot easier to work with than XML (but I hate XML so take that with a grain of salt). As far as a central configuration, I'm not sure what you're trying to accomplish but it sounds like something that can be solved using remote actor creation. Again, see the Remoting documentation.
Easy extraction of a node from this configuration file(Possibly with xpath).
Akka provides a lookup method .actorFor. There's no need to go to the configuration file once the system is up and running.
If so is there a load balancing example in akka or proxy example?
Google is your friend.