I'm setting up a polymorphic cube on top of a horizontal one as described on the confluence site (http://support.quartetfs.com/confluence/display/AP4/Polymorphic+scalability+on+top+of+horizontal+scalability), but it anoys me that it seems I need to have one of the horizontal nodes configured differently from all the others (the one that participates in the polymorphic cluster). It is quite convenient to be able to deploy the same configuration to all the nodes of the horizontal cluster.
Going all the way back to the spring configuration, I guess I could make a conditional configuration to get around this, but does anyone have a more elegant solution to this?
If you want all your nodes to have the same configuration, you could define a polymorphic pivot on each node with the autoStart property set to false (please refer to http://support.quartetfs.com/confluence/display/AP4/Distribution%27s+properties#Distributionsproperties-autoStart).
However, you'll then have to start one of them: this can be achieved by using the monitoring beans for instance.
Another possibility would be to deploy your horizontal nodes "as usual", then start an additional "proxy" node which will participate to both horizontal and polymorphic clusters. This extra node does not need any data: it's basically an empty horizontal pivot with a polymorphic pivot on top of it.
Related
Suppose I have a graph like this:
Cytoscape graph
The nodes 'lipid nanoparticle' and 'LNP' are synonyms. How can I identify nodes that represent synonyms and merge them in Cytoscape?
I searched Cytoscape App Store, but didn't manage to find a suitable app.
Sorry -- I don't know of an app that would automatically detect synonyms and merge them. You can certainly merge nodes using groups, but you would have to do that manually by selecting the two nodes, grouping them, and then collapsing them. All of the edges for the two nodes would then connect (as meta-edges) to the group node.
-- scooter
The iceberg documentation discusses using merge-on-read when deleting data. The documentation also refers to doing position deletes versus equality deletes. It seems straight forward to specify that I want merge-on-read in the table properties.
I've looked through the iceberg documentation and also found a half dozen external sites that talk about the pro's and con's of each method, but none of them describe how to specify position versus equality. Is this a table property? How do I choose a method?
I'm using spark 3.3 on EMR with scala/python
You don't need to specify POS or EQ delete. These two delete methods are automatically selected within the engine based on different scenarios.
To better use iceberg, you may need to pay attention to the following:
Use merge-on-read or cory-on-write
Merge files by specified policy
Expired snapshots and data deletion
Hope it helps you.
If both spark commands do almost the same thing, what should I consider when choosing one or the other?
Basically it is just a matter of the style you'd like to work with. Spark will generate a plan for the actual execution either way
One point for SQL is that it is relatively easier to generate if you need that
We've a net of vending machines of a few types and we have common API to rule them and get data from our vendors. The aim is to show live graphical schema for this net in a browser. The schema should include icons of machines, centers, servers etc. and the lines, connecting the objects with each other.
It's evident that the topography is flexible. We can set up new machines, change bindings, etc. Thus the schema should be traced automatically: I wish to give it some objects and relations as an array or JS object and see a graphical schema in the browser.
All the object should be clickable. I wish to click to the vendor icon and get statistics for it.
And last but not the least, this should work real-time. An operator should monitor this live schema, and, if trouble occurs, take some actions.
Back-end doesn't cause problems. I can do a DB and push all business-logic to server-side. But I wonder, is there a perfect way to display such stuff at front-end? Is there a ready-made solution for such kind of diagram?
Well, I don't think a ready-made solution of such a specific set of requirements exists (but I could easily be wrong on that). You could however take a look at D3. D3 is a Javascript 'data-driven' library to create dynamic charts and graphs. Maybe you can find something useful for your use case, as the library is quite flexible and offers many features.
Often I would have an unit and node object. Units are required to know which node they are at and nodes have to know the units its holding. This means that they each have a reference to each other. The problem I have is that I can see this getting messy since moving a unit to a new node means also having to update the reference for the nodes too. Is there a easier way to model/organize this relationship? This specific example is in lua but the question applies to any language.
It may be easiest to manage one side using a caching protocol. If the information changes, invalidate the cache. Then, when the side needs the information again, it obtains it.
In your example, perhaps the node has an authoritative list of units, while each unit only caches which node it is on. Perhaps these units are stopped and started, and the unit can simply look up which node it is attached to when it starts?