I am working with the VSO REST API and have a question on how Iteration and Area ID's are assigned. Specifically, why is it when I assign a work item to the root Iteration or Area the ID that is returned for the WIT is not returned when I query the classification nodes?
For example, imagine I have this hierarchy when I query /DefaultCollection/my project/_apis/wit/classificationnodes?$depth=2
My Project: id=1234
Area 1: id=5678
Area 2: id= 9012
And I then query for a work item using /DefaultCollection/_apis/wit/workItems/1?$expand=all
If the work item is in Area 1 or Area 2, the System.AreaId field is as expected (5678 and 9012, respectively). However, if I assign the work item to My Project, the System.AreaID is some value that is not included when I query for all classification nodes. There appears to be some kind of relationship between the ID's as they are serial (e.g. the ID returned by the classification node query is 1232 for the area and 1233 for the iteration), but I can't seem to find a way to query to get the actual ID returned by the work item query.
In fact, not only is the ID returned for a work item not present when I query for all classification nodes, if I assign the work item to both the root iteration and area, the ID returned for both fields is the same value that is not included in the classification node query.
What I need is a way to look at a work item and figure out the area and iteration it belongs to. I could probably do something with the path field strings that are returned, but that seems error prone since users can change them.
****Edit****
The above appears to be a bug in the REST API, but for anyone who comes across this post there is a way to get a usable iteration ID by the path string. Structure your REST call like so:
/DefaultCollection/[Project Name]/_apis/wit/classificationnodes/iterations/Release 1/Sprint 1 (etc.)
I have never done this with ID. I only use the path. In the classification service you can get the node by path easily enough.
For example, using the REST API - you can access this url to get the data about a specific iteration:
/DefaultCollection/[Project Name]/_apis/wit/classificationnodes/iterations/[Release X]/[Sprint Y]
Note that trying to access the default iteration path (the project name instead of a specific iteration) will return an error:
/DefaultCollection/[Project Name]/_apis/wit/classificationnodes/iterations/[Project Name]
will give :
{"$id":"1","innerException":null,"message":"VS402485: The node name is not recognized: [Project Name]","typeName":"Microsoft.TeamFoundation.WorkItemTracking.Server.Metadata.WorkItemTrackingTreeNodeNotFoundException, Microsoft.TeamFoundation.WorkItemTracking.Server","typeKey":"WorkItemTrackingTreeNodeNotFoundException","errorCode":0,"eventId":3200}
So if you do batch work, you have to filter those before querying the api.
There are three ways of identifying an Area (everything I post equally applies to Iterations also). The Path (string), the ID (int) and a Guid. each of them are used in different ways, and have different ramifications.
For example renaming an Area, does NOT change it's identity, therefore does not update a work item (the path returned for in a workitem is dynamic).
It is also possible to delete and recreate and identical path, but it will have a different ID.
The GUID is used primarily for the Excel Reports (such as are parent of the SharePoint portal)
Depending on how you want things to react determines the appropriate element to use.
I have not seen any issues with the ID that you mention, and if you could create a simple repro, I would be glad to look at it.
david(dot)corbin(at)dynconcepts(dot)com
Related
regarding to asked question here :
suppose that we have ProductCreated and ProductRenamed events which both contain the title of the product.now we want to query EventStoreDB for all events of type ProductCreated and ProductRenamed with the given title.i want all these events to check whether there is any product in the system which has been created or renamed to the given title, so that i could throw the exception of repetitive title in the domain
i am using MongoDB for creating UI reports from all the published events and everything is fine there.but for checking some invariants, like checking for unique values, i have to either query the event store for some events along with their criteria and by iterating over them, decide whether there is a product created with the same title which has not renamed or a product renamed with the same title.
for such queries, the only way that event store provides is creating a one-time projection with the proper java script code which filters and emits required events to a new stream.and then all i have to do is to fetch events from the new generated stream which is filled by the projection
no the odd thing is, projections are great for subscriptions and generating new streams, but they seem to be odd for doing real time queries.immediately after i create a projection with the HTTP api, i check the new resulting stream for the query result, but it seems that the workers has not got the chance to elaborate on the result and i get 404 response.but after waiting for a bunch of seconds, the new streams pops out and gets filled with the result.
there are too many things wrong with this approach:
first, it seems that if the event store is filled with millions of events across many streams, it wont be able to process and filter all of them immediately to the resulting stream.it does not create the stream immediately, let alone the population.so i have to wait for some time and check for the result hoping the the projection is done
second, i have to fetch multiple times and issue multiple GET HTTP commands which seems to be slow.the new JVM client is not ready yet.
Third, i have to delete the resulting stream after i'm done with the result and failing to do so will leave event store with millions of orphan query result streams
i wish i could pass the java script to some api and get the result page by page like querying MongoDB without worrying about the projection, new streams and timing issues.
i have seen a query section in the Admin UI, but i dont know whats that for, and unfortunetly the documentation doesn't help much
am i expecting the event store to do something that is impossible?
do i have to create a bounded context inner read model for doing such checks?
i am using my events to dehyderate the aggregates and willing to use the same events for such simple queries without acquiring other techniques
I believe it would not be a separate bounded context since the check you want to perform belongs to the same bounded context where your Product aggregate lives. So, the projection that is solely used to prevent duplicate product names would be a part of the same context.
You can indeed use a custom projection to check it but I believe the complexity of such a solution would be higher than having a simple read model in MongoDB.
It is also fine to use an existing projection if you have one to do the check. It might be not what you would otherwise prefer if the aim of the existing projection is to show things in the UI.
For the collection that you could use for duplicates check, you can have the document schema limited to the id only (string), which would be the product title. Since collections are automatically indexed by the id, you won't need any additional indexes to support the duplicate check query. When the product gets renamed, you'd need to delete the document for the old title and add a new one.
Again, you will get a small time window when the duplicate can slip in. It's then up to the business to decide if the concern is real (it's not, most of the time) and what's the consequence of the situation if it happens one day. You'd be able to find a duplicate when projecting events quite easily and decide what to do when it happens.
Practically, when you have such a projection, all it takes is to build a simple domain service bool ProductTitleAlreadyExists.
How do you quickly get the maximum (or minimum) value for a property of all instances of a relationship? You can assume the machine I'm running this on is well within the recommended spec's for the cpu and memory size of graph and the heap size is set accordingly.
Facts:
Using Neo4j v2.2.3
Only have access to modify graph via Cypher query language which I'm hitting via PHP or in the web interfacxe--would love to avoid any solution that requires java coding.
I've got a relationship, call it likes that has a single property id that is an integer.
There's about 100 million of these relationships and growing
Every day I grab new likes from a MySQL table to add to the graph within in Neo4j
The relationship property id is actually the primary key (auto incrementing integer) from the raw MySQL table.
I only want to add new likes so before querying MySQL for the new entries I want to get the max id from the likes, so I can use it in my SQL query as SELECT * FROM likes_table WHERE id > max_neo4j_like_property_id
How can I accomplish getting the max id property from neo4j in a optimal way? Please indicate the create statement needed for any index as well as the query you'd used to get the final result.
I've tried creating an index as follows:
CREATE INDEX ON :likes(id);
After the index is online I've tried:
MATCH ()-[r:likes]-() RETURN r.i ORDER BY r.id DESC LIMIT 1
as well as:
MATCH ()-[r:likes]->() RETURN MAX(r.id)
They work but take freaking forever as the explain plan for both indicate no indexes being used.
UPDATE: Holy $?##$?!!!! It looks like the new schema indexes aren't functional for relationships even though you can create them and show them with :schema. It also looks as if there's no way with cypher directly to create Legacy Indexes which look like they might solve this issue.
If you need to query relationship properties, it is generally a sign of a model issue.
The need of this query reveals you that you would better extract these properties into a node, that you'll then be able to query faster.
I don't say it is 100% the case, but certainly 99% of the people seen so far with the same problem has been demonstrating this model concern.
What is your model right now ?
Also you don't use labels at all in your query, likes have a context bound to the nodes.
I would like create a Flat list of work items query in TFS in which the results contain all of the specified PBI and Bug cases and any Task cases that have no parent.
It's that Task with no parent part that has me perplexed. I cannot see a way that I can do what seems so obvious such as (Parent Link Count = 0) because that attribute is not exposed to me though, strangely, some other link type counts are.
Any ideas?
You need to change the type of your query to the Direct Links query, then choose the option to pull back all work items without any matching links. The results will still be a flat list.
In my recent question, Modeling conditional relationships in neo4j v.2 (cypher), the answer has led me to another question regarding my data model and the cypher syntax to represent it. Lets say in my model, there is a node CLT1 that is what I'll call the Source node. CLT1 has relationships to other 286 Target nodes. This is a model of a target node:
CREATE
(Abnormally_high:Label1:Label2:Label3:Label4:Label5:Label6:Label7:Label8:Label9:Label10
{Pro1:'x',Prop2:'y',Prop3:'z'})
Key point: I am assuming the string after the CREATE clause is
The ID of this target node
The ID is significant because its content has domain-specific meaning
and is query-able.
in this case its the phrase ...."Abnormally_high".
I made this assumption based on the movie database example.
CREATE (Keanu:Person {name:'Keanu Reeves', born:1964})
CREATE (Carrie:Person {name:'Carrie-Anne Moss', born:1967})
The first strings after CREATE definitely have domain-specific meaning!
In my earlier post I discuss Problem 2. I find that problem 2 arises because among the 286 target nodes, there are many instances where there was at least one more Target node who shares the identical ID. In this instance, the ID is "Abnormally_high". The other Target nodes may differ in the value of any of Label1 - Label10 or the associated properties.
Apparently, Cypher doesn't like that. In Problem 2, I was discussing the ways to deal with the fact that cypher doesn't like using the same node ID multiple times even though the labels or properties were different.
My problem are my assumptions about the Target node ID.
AM I RIGHT?
I am now thinking that I could instead use this....
CREATE (CLT1_target_1:Label1:Label2:Label3:Label4:Label5:Label6:Label7:Label8:Label9:Label10
{name:'Abnormally_high',Prop2:'y',Prop3:'z'})
If indeed the first string after the CREATE clause is an ID, then all I have to do is put a unique target node identifier.... like CLT1_target_1 and increment up to CLT1_target_286. If I do this, then I can have the name as a property and change whatever label or property I want.
Do I have this right?
You are wrong. In Cypher, a node name (like "Abnormally_high") is just a variable name that exists for the lifetime of the query (and sometimes not even that long). The node name used in a Cypher query is never persisted in any way, and can be any arbitrary string.
Also, in neo4j, the term "ID" has a specific meaning. The neo4j DB will automatically assign a (currently) unique integer ID to each new node. You have no control over the ID value assigned to a node. And when a node is deleted, neo4j can reassign its ID to a new node.
You should read the neo4j manual (available at docs.neo4j.org), especially the section on Cypher, to get a better understanding.
I haven't attempted to work with graphs in Rails before, and am curious as to the best approach. Some background:
I am making a Rails 3 site and thought it would be interesting to store certain objects and their relationships as a graph, where each object is a node and some are connected to show that the two objects are related. The graph does contain cycles, and there wouldn't be more than 100-150 nodes in the graph (probably only closer to 50). One node probably wouldn't have more than five edges, with an average of three to four edges per node.
I figured a simple join table with two columns (each the ID of the object) might be the easiest way to do it, but I doubt it's the best way. Another thought was to use a plugin such as acts_as_tree (which doesn't appear to be updated for Rails 3...) or acts_as_tree_with_dotted_ids, but I am unsure of their ability to work with cycles rather than hierarchical trees.
the most I would currently like is to easily traverse from one node to its siblings. I really can't think of a reason I would want to traverse to a node's sibling's sibling, which is why I was considering just making an SQL join table. I only want to have a section on the site to display objects related to a specified object, and this graph is one of the ways I am specifying relationships.
Advice? Things I should check out? Thanks!
I would use two SQL tables, node and link where a link is simply two foreign keys, source and target. This way you can get the set of inbound or outbound links to a node by performing an SQL select query by constraining the source or target node id. You could take it a step further by adding a "graph_id" column to both tables so you can retrieve all the data for a graph in two queries and build it as a post-processing step.
This strategy should be just as easy (if not easier) than finding, installing, learning to use, and implementing a plugin to do the same, IMHO.
Depending on whether your concern is primarily about operations on graphs, or on storage of graphs, what you need is potentially quite different. If you want convenient operations on graphs, investigate the gem "rgl" (ruby graph library). It has implementations of most of the basic classic traversal and search algorithms.
If you're dealing with something on the order of 150 nodes, you can probably get away with a minimalist adjacency list representation in the database itself, or incidence list. Then you can feed that into RGL for traversal and search operations.
If I remember correctly, RGL has enough abstraction that you may be able to work with an existing class structure and you simply provide methods to get adjacent nodes.
Assuming that it is a directed graph, use a mapping table such as
id | src | dest
where src and dest are FKs to your object table.
If your objects are not all of the same type, either have them all inherit a ruby class or have another table:
id | type | type_id
Where type is the type of object it is and type_id is its id in another table.
By doing this, you should be able to get an array of objects for each object that it points to using:
select dest
from maptable
where dest = self.id
If you need to know its inbound edges, you can preform the same type of query using src instead of dest.
From there, you should be able to easily write any graph algorithms that you want. If you need weights, you can modify the mapping table as such.
id | src | dest | weight