Hi
I am developing a search function for an web application with Lucene.Net and NHibernate.Search. The application is used by a lots of companies but is runned as a single service, using different databases for different companies. Therefore I would need an index directory for each database rather than one directory for the entire application. Is there a way of achieve this in Lucene.Net?
I have also considering storing the indexes for each company in there respecitive database but havent found any satisfying compontents for this. I have read about Compass and JdbcDirectory for Java but I need something for C# or NHibernate. Does anyone know if there is a port of JdbcDirectory or something simular for C#?
Hmm, it looks like you can't change anything at the session factory level using normal nhibernate.search. You may need separate instances of a configuration, or maybe try something along the lines of Fluent NHibernate Search to ease the pain.
Piecing it together from the project's wiki it appears you could do something like this to spin up separate session factories pointing to different databases / index directories:
Fluently.Configure()
.Database(SQLiteConfiguration.Standard.InMemory())
.Search(s => s.DefaultAnalyzer().Standard()
.DirectoryProvider().FSDirectory()
.IndexBase("~/Index")
.IndexingStrategy().Event()
.MappingClass<LibrarySearchMapping>())
.BuildConfiguration()
.BuildSessionFactory();
The "IndexBase" property and the connection are the parts you'll need to define per customer. Once you get the session factories set up you could resolve them using whatever strategy you use currently.
Hope it helps
Related
We are looking into OrientDB as our persistency solution behind a restful web service, because a GraphDB would be a perfect match for our use case. One of the things we have noticed is that entities (both Vertex and Edges) are uniquely identified by a ORecordId, containing the '#${clusterId}:${clusterPosition}'. In a restful API, based on my personal experience from relational DB's, you typically have several solutions to identify entities uniquely, for example:
UUID's, generated in code and persisted on DB level
Long/Int values, generated on DB level incrementally
etc...
The problem is that the format "#${clusterId}:${clusterPosition}" is not really URL/REST friendly (example: .../api/user/[#${clusterId}:${clusterPosition}]/address). Do you have any advice/experience on how you would deal with this, keeping in mind that you need a bi-directional mapping between the ORecordId and the "RestFulFriendlyId"?
Any hints and best practices based on experience would be truly appreciated....
Best regards,
Bart
We're looking into using HashID. http://hashids.org/
There are some minor concerns we have still, but theoretically, HashID should get you a hashed Rid, which is also convertible, so it won't take up more storage space (like with a UUID). It will just take a small bit of CPU time.
Please note, this little tool is not in any way a true hash, as in, it makes it very hard to crack the hash. It is more about good obfuscation. If you are at all worried about the Rids being known, this isn't a proper solution.
Scott
Actually, I'd say the RIDs are very RESTful, if you do this:
.../domain.com/other-segments/{cluster}/{position}/...
Since clusters are a "superset" of a specific class (i.e. one class will have one or more clusters), this can be thought of as identifying the target data object by type/record. I'm not sure what backend you're using, but extracting those two URL segments and recombining them to #x:y should be a fairly simple (and maybe mostly automatic) task.
I'm maintaining an API to manage several IBM commerce data systems.
What I need is to create, edit or remove attributes, their values and their descriptions. Basically, I need to work using the ATTR, ATTR_DESC, ATTRVAL and ATTRVAL_DESC tables.
I thought there was an AttributeCreateCmd, but I couldn't find it. What I found was the AttributeValueAddCmd command, but it seems that it is not working (maybe I'm not using it correctly). I need to handle the attributes
among the attribute values.
I tried also with AttributeBean and AttributeDataBean, but it seems that that's not the stuff I need.
What I know is the model objects that I need to work with are Attr and AttrVal, but I don't know what *Cmd, *Bean or whatever I need to maintain that data.
Is there something that does exactly what I need?
Ok, so to manage the ATTR data manually, seems you have to use AttributeDictionaryMediator, but I was unable to use it.
Finally I implemented the commands to access the tables, to use them wherever I need them.
Is it possible to create namespaces in Redis?
From what I found, all the global commands (count, delete all) work on all the objects. Is there a way to create sub-spaces such that these commands will be limited in context?
I don't want to set up different Redis servers for this purpose.
I assume the answer is "No", and wonder why wasn't this implemented, as it seems to be a useful feature without too much overhead.
A Redis server can handle multiple databases... which are numbered. I think it provides 32 of them by default; you can access them using the -n option to the redis-cli shell scripting command and by similar options to the connection arguments or using the "select()" method on its connection objects. (In this case .select() is the method name for the Python Redis module ... I presume it's named similarly for other libraries and interfaces.
There's an option to control how many separate databases you want in the configuration file for the Redis server daemon as well. I don't know what the upper limit would be and there doesn't seem to be a way to dynamically change that (in other words it seems that you'd have to shutdown and restart the server to add additional DBs). Also, there doesn't seem to be an away to associate these DB numbers with any sort of name nor to impose separate ACLS, nor even different passwords, to them. Redis, of course, is schema-less as well.
If you are using Node, ioredis has transparent key prefixing, which works by having the client prepend a given string to each key in a command. It works in the same way that Ruby's redis-namespace does. This client-side approach still puts all your keys into the same database, but at least you add some structure, and you don't have to use multiple databases or servers.
var fooRedis = new Redis({ keyPrefix: 'foo:' });
fooRedis.set('bar', 'baz'); // Actually sends SET foo:bar baz
If you use Ruby you can look at these gems:
https://github.com/resque/redis-namespace
https://github.com/jodosha/redis-store
We're running an ASP.NET database application which uses HiLo to generate ids for entities. On top of this application, we have several websites using the same database. What we're seeing is that we run out of ids and the ID-column becomes a negative number.
We suspect this has something to do with the generator. As multiple websites run on top of the same codebase and database and probably the HiLo algorithm quickly starts generating ids which are outside of the bigint-range (with quickly being relative of course).
Is it possible to configure the generator in such a way that it also uses the gaps (of which there are quite a few) in the Id-sequences, instead of bluntly increasing the value whenever it feels that's necessary?
Would that be a solution? Or should we be doing something else altogether?
what is your max_lo set to?
The formula to generate id is as follows
h = high sequence (starting at 0)
l_size = size of low block
l = low sequence (starting at 1)
ID = h*l_size + l
Maybe your max_lo is set to high?
You can switch to Guid.Comb generator if this is possible or use int64 for ids. Take a look here for making final decision regarding what generator to use.
I've come across the same problem and also haven't been able to find a suitable answer.
We also have a site which is being ran as separate websites with each site in its own separate application pool, all on the same webserver.
Pragmatically, you'd be better off just switching to Identity mapping, if your databas supports it. It shouldn't be too hard to do, you should be able to modify your database schema with a bit of TSQL and the ID mappings with a bit of search/replace.
Do you have a concept similar to UoW in your application? Because a downside to identity generation is that it'll break the UoW (early inserts in order to get the identifier). It might be a price worth paying, though.
In my case the system could easily exist as a single site/app pool (it's multi-tenant on a single database, with single shared connection string, and is designed to run as a single instance on a webserver) so I'm going to test that before I make the jump to database-identities..
I am developing a Novell Identity Manager driver for Salesforce.com, and am trying to understand the Salesforce.com platform better.
I have had really good success to date. I can read pretty much arbitrary object classes out of SFDC, and create eDirectory objects for them, and what not. This is all done and working nicely. (Publisher Channel). Once I got Query events mapped out, most everything started working in the Publisher Channel.
I am now working on sending events back to SFDC (Subscriber channel) when changes occur in eDirectory.
I am using the upsert() function in the SOAP API, and with Novell Identity Manager, you basically build the SOAP doc, and can see the results as you build it. (You can do it in XSLT or you can use the various allowed tokens to build the document in DirXML Script. I am using DirXML Script which has been working well so far.).
The upshot of that comment is that I can build the SOAP document, see it, to be sure I get it right. Which is usually different than the Java/C++ approach that the sample code usually provides. Much more visual this way.
There are several things about upsert() that I do not entirely understand. I know how to blank a value, should I get that sort of event. Inside the <urn:sObjects> node, add a node like (assuming you get your namespaces declared already):
<urn1:fieldsToNull>FieldName</urn1:fieldsToNull>
I know how to add a value (AttrValue) to the attribute (FieldName), add a node like:
<FieldName>AttrValue</FieldName>
All this works and is pretty straight forward.
The question I have is, can a value in SFDC be multi-valued? In eDirectory, a multi valued attribute being changed, can happen two ways:
All values can be removed, and the new set re-added.
The single value removed can be sent as that sort of event (remove-value) or many values can be removed in one operation.
Looking at SFDC, I only ever see Multi-picklist attributes that seem to be stored in a single entry : or ; delimited. Is there another kind of multi valued attribute managed differently in SFDC? And if so, how would one manipulate it via the SOAP API?
I still have to decide if I want to map those multi-picklists to a single string, or a multi valued attribute of strings. First way is easier, second way is more useful... Hmmm... Choices...
Some references:
I have been using the page Sample SOAP messages to understand what the docs should look like.
Apex Explorer is a kicking tool for browsing the database and testing queries. Much like DBVisualizer does for JDBC connected databases. This would have been so much harder without it!
SoapUi is also required, and a lovely tool!
As far as I know there's no multi-value field other than multi-select picklists (and they map to semicolon-separated string). Generally platform encourages you to create a proper relationship with another (possibly new, custom) table if you're in need of having multiple values associated to your data.
Only other "unusual" thing I can think of is how the OwnerId field on certain objects (Case, Lead, maybe something else) can be used to point to User or Queue record. Looks weird when you are used to foreign key relationships from traditional databases. But this is not identical with what you're asking as there will be only one value at a time.
Of course you might be surpised sometimes with values you'll see in the database depending on the viewing user's locale (stuff like System Administrator profile becoming Systeembeheerder in Dutch). But this will be still a single value, translated on the fly just before the query results are sent back to you.
When I had to perform SOAP integration with SFDC, I've always used WSDL files and most of the time was fine with Java code generated out of them with Apache Axis. Hand-crafting the SOAP message yourself seems... wow, hardcore a bit. Are you sure you prefer visualisation of XML over the creation of classes, exceptions and all this stuff ready for use with one of several out-of-the-box integration methods? If they'll ever change the WSDL I need just to regenerate the classes from it; whereas changes to your SOAP message creation library might be painful...