We are running multiple fuseki servers. We want to run Sparql queries using data from any number of them. That means using the SERVICE key word, no problem.
How do we set up authentication in Fuseki server A to access Fuseki server B?
Presumably it is done using a service .ttl file, but after waterboarding google for an hour it still won't give an straight answer.
Related
I'm trying to run a SPARQL query on Wikidata, but it times out. I'd like to download a dump and index it in some database, so I can run local SPARQL queries using HTTP requests. I also need to support Wikidata-specific extensions like SERVICE wikibase:label. I've downloaded an RDF dump. What are the next steps?
Wikimedia has documentation on how to run your own SPARQL endpoint from one of their dumps. They also have an updater that streams updates from their servers, to keep your endpoint up-to-date.
You won't need to do anything special to support their extensions, it is included by default.
I recommend using a reverse proxy (like nginx or apache) with http auth in production, the admin dashboard is accessible by default.
I have to create dozens of custom SPARQL endpoints in Virtuoso and assign a particular named graph to a particular endpoint.
I know there is a Conductor GUI but I would not like to create endpoints manually.
How do I create an endpoint (say, on port 8899) via Virtuoso ISQL command line?
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.
ActiveMQ broker setup:
Broker is running on machine: hostA
Clients from different host can connect to my broker instance running on hostA, there can be any number of client from any host.
Is there a way to find out how many clients are connected to broker and also list which tell me how many connection from each host is there to my broker.
I want to do this without making assumption about number of hosts.
I can do this by using lsof command and some parsing over output, but I am in situation where I can not use this.
Is there any feature provided by ActiveMQ command line utility activemq-admin.
You can get to pretty much any Mbean attribute ActiveMQ exposes via the activemq-admin. There are no attributes or operations that give you a quick count of connections from specific clients. You will have to do some work on your end to get all the details you want, but all the raw data is there.
Examples:
Broker Stats:
activemq-admin query --objname type=Broker,brokerName=localhost
Connection Stats
activemq-admin query --objname type=Broker,brokerName=localhost,connector=clientConnectors,connectorName=<transport connector name>,connectionViewType=clientId,connectionName=*
See full doc here.
NOTE: Documentation as of this writting has not be updated to take into account the Mbean changes made in AMQ. References to Object names in examples are not correct.
You can get the object name (or example sytax) from JMX (using jconsole or visual vm for example) from the MBeanInfo. Each object name wills stat something like org.apache.activemq:type. For the script, remove the "org.apache.activemq:" and you should be in business for any thing you need from JMX via the script.
I think you may also look into using Jolokia with your broker. Although not compatible with the activemq-admin script, you can reach everything you can from the activemq-admin script, but also have access to all of the operations. In the past I've heavily used the activemq-admin script for local monitoring/command line administration of the broker, but have started converting everything to hit the Jolokia service. But again, activemq-admin will give you a way to access what you are looking for here.
I have a Web Server implemented using dot net MVC4. There are clients connected to this web server which perform some operations and upload live logs to the server using WebClient.UploadString method. Sending these logs from client to server is being done in group of 2500 characters at a time.
Things work fine until 2-3 client upload logs. However when more than 3 clients try to upload logs simultaneously they start receiving "http 500 internal server error".
I might have to scale up and add more slaves but that will make the situation worse.
I want to implement Jenkins like live logging, where logs from slave are updated live.
Please suggest some better and scalable solution to this problem.
Have you considered looking into SignalR?
It can be used for anything from instant messaging to stocks! I have implemented both a chatbox, and a custom system that sends off messages, does calculations and then passes them back down to client. It is very reliable, there are some nice tutorials, and I think it's awesome.