I am trying to implement just half of the SNMP functionality. On certain events, I want to create trap corresponding to each event. I am using C and Linux.
What would be the simplest way to achieve this? Do I need to use any open source utilities?Some of the events that I want to notify are very specific to my application. How to go about implementing this case?
I am new to SNMP. I have couple of basic questions: How agent and manager figure about what property i.e. object is being referred to? Do they both parse the MIB? How is MIB shared between agent and manager?
The easiest way is to execute Net-SNMP executable called snmptrap,
http://www.net-snmp.org/tutorial/tutorial-5/commands/snmptrap.html
Of course, you can also link to its underlying library so as to call the C functions directly.
About your basic questions on SNMP, you should start from a book, such as Essential SNMP or Understanding SNMP MIBs.
Related
I have a PAM application that makes use of a particular PAM module for authentication chores. My question is, what is the best for the module to share an arbitrary string of bytes with the application?
My understanding of the PAM API is that, in general, the application must use the pam_get_item() call in order to obtain data from the module. However, the item types that can be shared are very limited, and they do not seem to accommodate for what I need - with the possible exception of the PAM_CONV item type. If anybody in this forum has experience with this kind of thing their feedback would be much appreciated.
After some experimentation I think I found the answer. In essence, the application has to define a PAM conversation callback in which a pointer to a data buffer is provided. The PAM module has to invoke the callback at the appropriate time, and copy the appropriate data into that buffer. The application will simply obtain the desired data by reading the contents of the buffer.
This will of course have to be carefully choreographed by the application, and the module may have to be modified to invoke the callback at the right time. The idea is simple though.
I am learning a lot as a result of posting to this forum, even if I don't seem to be getting any feedback when it comes to PAM-related questions.
I think you can use PAM_CONV. as it says:
The PAM library uses an application-defined callback to allow a direct
communication between a loaded module and the application. This
callback is specified by the struct pam_conv passed to pam_start(3) at
the start of the transaction.
I need to implement the following logic - I send a message to the user, and if he doesn't reply, I send it again after 12 hours.
I wonder what is the best way to do this? I was thinking about using Akka.NET - after a certain amount of time the actor would check if the user replied to my message and if not, would send it again.
Is there maybe an easier way? If not, there are some questions for Akka.NET
Do you know any good sources where I can see how this library should be used in ASP.NET Core? The documentation is not clear enough for me.
Where to keep the actors and the logic associated with them? In a separate project? Where can I create an actorSystem?
I'm new to this topic, thank you in advance for all the answers.
I theory you could just use standard actor system schedule a message order to resend an email after 12h, but this has natural problems with a fact, that if your process will crash, all of its in-memory state will be lost.
In practice you could use one of two existing plugins, which give you durable schedules:
Akka.Persistence.Reminders which works on top of Akka.Persistence, so you can use it on top of any akka.net persistence plugin.
Another way is to use Akka.Quartz.Actor which offers dedicated actors on top of Quartz.NET and makes use of Quartz's persistence capabilities.
A lot of our use cases for Biztalk involve simply mapping and routing HL7 2.x messages from one system to another. Implementing maps and associating them to send/recieve ports is generally straightforward, but we also need to do some content based filtering on the sending side.
For example, we may want to only send ADT A04 and ADT A08 messages to system X if the sending facility is any 200 facilities (out of a possible 1000 facilities we have in our organization), but System Y needs ADT A04, A05, A8 for a totally different set of facilities and only for renal patients.
Because we're just routing messages and not really managing business processes here, utilzing orchestrations for the sole purpose to call out to the business rule engine is a little overkill here, especially considering that we'd probably need a seperate orchestration for each ADT type because of how schemas work. Is it possible to implement filter rules like this without using using orchestrations? The filters functionality of send ports looks a little too rudimentary for what we need, but at the same time I'd rather not develop and manage orchestrations.
You might be able to do this with property schemas...
You need to create a property schema and include the properties (from the other schemas) that you want to use for routing. Once you deploy the schema, those properties will be available for use as a filter in the send port. Start from here, you should be able to find examples somewhere...
As others have suggested you can use a custom pipeline component to call the Business Rules Engine.
And rather then trying to create your own, there is already an open source one available called the BizTalk Business Rules Engine Pipeline Framework
By calling BRE from the pipeline you can create complex rules which then set simple context properties on which you can route your messages.
Full disclosure: I've worked with the author of that framework when we were both at the same company.
I want to write an event loop single threaded web server to deal with each request in Racket.
I see there are select method in unix that I can call,
Is there anything similar in Racket API that I can call? or I should write my own select method which is to polling the ready fds?
Thanks in advance!
Apologies if I'm misunderstanding your question, but it sounds like you'll probably want to use tcp-listen on certain ports; success here will create input ports. In order to synchronize on multiple open input ports, check out "synchronizable events"; you can use 'sync' on a whole bunch of open ports simultaneously.
I would be remiss if I failed to add that there's a complete web server included with Racket; I'm assuming that you have your own reasons for wanting to re-implement this.
I’m a complete newbie at BizTalk and I need to create a BizTalk 2006 application which broadcasts messages in a specific way. I’m not asking for a complete solution, but for advise and guidelines, which capabilities of BizTalk I should use.
There’s a message source, for simplicity, say, a directory where the user adds files to publish them. There are several subscribers, each having a directory to receive published files. The number of subscribers can vary in the course of exploitation of the program. There are also some rules which determine if a particular subscriber needs to receive a particular file, based on the filename. For example, each subscriber has a pattern or mask of filename which files they receives must match. Those rules (for example, patterns) can change in time as well.
I don’t know how to do this. Create a set of send ports at runtime, each for each destination? Is it possible? Use one port changing its binding? Would it work correctly with concurrent sendings? Are there other ways?
EDIT
I realized my question may be to obscure and general to prefer one answer over another to accept. So I just upvoted them.
You could look at using dynamic send ports to achieve this - if your subscribers are truly dynamic. This introduces a bit of complexity since you'll need to use an orchestration to configure the send port's properties based on your rules.
If you can, try and remove the complexity. If you know that you don't need to be truly dynamic when adding subscribers (i.e. a subscriber and it's rules can be configured one time only) and you have a manageable number of subscribers then I would suggest configuring each subscriber using it's own send port and use a filter to create subscriptions based on message context properties. The beauty of this approach is that you don't need to create and deploy an orchestration and this becomes a highly performant and scalable solution.
If the changes to the destination are going to be frequent, you are right in seeking a more dynamic solution. One nice solution is using dynamic send ports and the Business Rules Engine. You create rule set for the messages you are receving. This could be based on a destination property or customer ID in the message. Using these facts, the rules engine can return a bunch of information like file mask, server name, ip address of deleiver server, etc. You can thenuse this information to configure the dynamic send in the orchestration. The real nice thing here is that you can update the rule set in the rules engine without redeploying the whole solution. As a newb, these are some advanced concepts, but not as diificult as you may think.
For a simpler solution, you might want to look at setting the FILE Send adapters properties via it's Propery Schema (ie. File name, Directory, etc.). You could pull these values from a database with a helper class inside an expresison shape. On each message ogig out, use the property shcema to set where the message will be sent and named. This way, you just update the database as things change.
Good Luck!