Redisson (https://github.com/redisson/redisson) throws org.redisson.client.RedisConnectionException when i'm trying to update some redisson variable and the underlying redis is down. So, why does it not mention in the code: something like
throws org.redisson.client.RedisConnectionException for all the methods ?
I wanted to use this library because it lets me set timeouts for individual entries of a hashmap. I'm going to use it in my production applications. Is it safe to use it ?
So, why does it not mention in the code: something like throws org.redisson.client.RedisConnectionException for all the methods ?
It's state of design
Is it safe to use it ?
Sure you can. Many companies across the world trust to Redisson. See used by section on project page.
Related
I need to store and load some data in a C++ application. This data is basically going to end up as a set of tables as per a relational database.
I write the data to tables using something like csv format, then parse them myself and apply the database logic I need in my C++ code. But it seems stupid to reinvent the wheel with this and end up effectively writing my own database engine.
However, using something like a MySQL database seems like massive overkill for what is going to be a single user local system. I have tried setting up a MySQL daemon on my Windows system and I found it rather complex and possibly even impossible without admin privileges. It would be a serious obstacle to deployment as it would need each user's system to have MySQL set up and running.
Is there a reasonable middle ground solution? Something that can provide me with a simple database, accessible from C++, without all the complexities of setting up a full MySQL install?
NB. I have edited this question such that I hope it satisfies those who have voted to close the question. I am not asking for a recommendation for a tool, or someone's favourite tool or the best tools. That would be asking which database engine should I use. I am asking for what tools and design patterns are available to solve a specific programming problem - i.e. how can I get access to database like functionality from a C++ program, without writing my own database engine, nor setting up a full database server. This is conceptually no different to asking e.g. How do I print out the contents of a vector? - it's just a bigger problem. I have described the problem and what has been done so far to solve it. My understanding from the On Topic Page is that this is within scope.
You can try sqlite.
Here are some simple code examples: https://www.tutorialspoint.com/sqlite/sqlite_c_cpp.htm
Is there any method to identify from which source an API is called? source refer to IOS application, web application like a page or button click( Ajax calls etc).
Although, saving a flag like (?source=ios or ?source=webapp) while calling api can be done but i just wanted to know is there any other better option to accomplish this?
I also feel this requirement is weird, because in general an App or a web application is used by n number of users so it is difficult to monitor those many API calls.
please give your valuable suggestions.
There is no perfect way to solve this. Designating a special flag won't solve your problem, because the consumer can put in whatever she wants and you cannot be sure if it is legit or not. The same holds true if you issue different API keys for different consumers - you never know if they decide to switch them up.
The only option that comes to my mind is to analyze the HTTP header and see what you can deduce from it. As you probably know a typical HTTP header looks something like this:
You can try and see how the requests from all sources differ in your case and decide if you can reliably differentiate between them. If you have the luxury of developing the client (i.e. this is not a public API), you can set your custom User-Agent strings for different sources.
But keep in mind that Referrer is not mandatory and thus it is not very reliable, and the user agent can also be spoofed. So it is a solution that is better than nothing, but it's not 100% reliable.
Hope this helps, also here is a similar question. Good luck!
I am looking for a good ldap library on Django, that would allow me to manage my ldap server :
adding, modifying, deleting entries
for groups, users, and all kind of objects
The library django-ldapdb looked promising, it offers a Model base class that can be used to declare ldap objects in a Django fashion (which is what we ideally want), however we've had some bugs with it, and furthermore it seems like it is not maintained any more.
Does somebody know a good library that could do the trick ? Otherwise I guess I'll just try to improve and debug django-ldapdb ...
Thanks !
sebpiq, you say you applied "one or two fixes" to django-ldapdb, would you care to share them? So far django-ldapdb meets my needs, but I'd be happy to integrate any fixes you might have.
When using ldapdb to query ldap with more results than the server allows instead of getting the partial list (of say the first 500 users) I get SIZELIMIT_EXCEEDED exception. Trying to change the code to catch that exception resulted in an empty result objects.
Anyone else had that problem?
I fixed that problem by changing the search_s function to use search_ext and read the results one by one until the exception happens.
http://www.python-ldap.org/doc/html/index.html
The beauty of Django is that you can use any python module within your application.
There is also django-auth-ldap which claims
LDAP configuration can be as simple as a single distinguished name template, but there are many rich options for working with User objects, groups, and permissions.
Actually, I have found out that with one or two fixes, django-ldapdb is a pretty good library. The only bad point is that it is not very actively maintained... I will use it anyways, because it is the best solution I have found.
I sometimes get
Could not find the ColdFusion Component or Interface Answer.
and simply doing a refresh fixes the problem.
This is not case where the program is being refreshed from ftp while I try to browse from it: no development is being done. But every once in a while I'll get it while trying to do a createobject.
Q: Is there a best practice for sleeping and trying again if instantiating a component fails?
Are you using a cluster of servers? If so perhaps you have one server misconfigured - perhaps a missing mapping - and when you get served from that server you see the issue? That might explain the way it seems to only sometimes happen.
By the way, instansiation of CFCs should always work - you should not be trying to code around this issue by sleeping and trying again.
Phillip, any chance this is on cf 9.0.1, and you're using the "import" keyword?
The reason I ask is that I've seen behavior -- and logged a bug report on it -- where if I have two different object creations on the same page (or in another CFC... doesn't matter), both from the same package, and I'm not using the fully qualified CFC name but instead am using import, then the first createObject() will succeed and the second will fail with the "could not find ... " error.
I wonder if something like that could be at work here.
I am currently working on a C++/COM project using ArcEngine(From ESRI). Aside from the fact that there is little to no support in terms of documentation (SDK is there.) Anyways, i am wondering if anyone here has had any experience in making the initialization process of ArcEngine faster. Right now it takes 30-35 seconds just to initialize the engine. Now we are going to be running several of these applications. Does anyone have any experience, with this?
Its a very werid and odd task, but ESRI's developer forums are no help. and i couldnt find anything on google.
Any ideas?
It's been almost a decade since I last played with ESRI stuff, so I can't help you with anything specific to ArcEngine.
Maybe you can pool instances? In the best case scenario you would be able to reuse ArcEngine instances, and could return an instance back to pool after you're done with it.
If that's not possible, you could at least try to have a number of instances ready to roll, although whether that is possible and/or useful depends a lot on the specifics of your app.
Is it really COM? In that case, the ArcEngine will be exposing a set of COM interfaces. COM interfaces are not magic, and not uniquely bound to one program. In fact, COM has explicit support for proxying. This is e.g. used by DCOM; you get a local proxy for the remote server.
In this case, it should be possible to write a custom COM proxy that fakes the initialization stuff but forwards everything else. Towards your client, the proxies COM interface is identical except faster. Towards ArcEngine, your proxy can wait quite long between calls.
Something that I have found useful with getting ESRI products to start faster (not necessarily ArcEngine, but this probably applies) is to specify the port number (generally 27004) in the registry where the license server is defined.
HKEY_LOCAL_MACHINE\SOFTWARE\ESRI\License\LICENSE_SERVER
HKEY_LOCAL_MACHINE\SOFTWARE\ESRI\ArcInfo\Workstation\8.0\LICENSE_SERVER
When you set this in installation or through the desktop administrator, it is generally something like: #yourserver.name
Change this to 27004#yourserver.name
Again this may not solve your issue, but if you're not doing it, it's worth a try. I've found it to speed things up in our environment, both using a license manager on a network and with a hardware dongle on the local machine.
Well from my understanding ArcEngine initialization, initializes a special COM environment.
You don't ever get any sort of real handle over the initialized environment. Can you somehow store a COM Enviroment and pass it to other programs. My current idea is:
Windows Service Running in Background with initialized ArcEngine. Program somehow queries the service, the service returns the COM Enviroment. Is this even possible?
I had a lot of grief with ESRI forums providing very little help. It feels like Arc* developers are largely on their own.
Using ArcEngine + .Net the initialization time for an application has been trivial (maybe 1 second?) in our environment -- are you using a slow remote server or is this JUST the engine with no network or maps being loaded?
Whenever I've had to deal with large data sets, ESRI has a pig though.
Good to see some discussion on SO of ESRI products! Not a lot here yet...
Exactly what line is taking 45 seconds? If I had to do some psychic debugging, I would guess that you are running into a problem with your license server.
Check that first.