Apache Solr Learning to Rank Feature and Model Stores

This short blog post wants to help you managing learning to rank feature and model stores in Apache Solr. Here I will list for you the main commands, while in the next post I will recap the most common errors that can occur during the manipulation of feature and model stores.

Learning to rank feature store

List

A feature store is a container of features.
A model uses features from only one feature store.
A feature store can be used by many models.
The list of the avaialble feature stores in the collection1 collection, is available at:

https://localhost:8983/solr/collection1/schema/feature-store

The response looks like:

{
  "responseHeader": {
       "status": 0,
       "QTime": 160
  },
  "featureStores": [
      "first_store",
      "second_store"
  ]
}

Where first_store and second_store are the available feature stores present in collection1.

Upload

To upload a feature store to a feature-store of a specific collection, we use the following curl command.

For the collection1 collection:

curl -XPUT "https://localhost:8983/solr/collection1/schema/feature-store/" --data-binary "@features.json" -H "Content-type:application/json"

Where features.json is the file containing the features (the feature store we want to upload).

For example:

[
    {
        "store": "first_store",
        "name": "feature_1",
        "class": "org.apache.solr.ltr.feature.ValueFeature",
        "params": {
            "value": "${feature_1}",
            "required": false
        }
    },
    {
        "store": "first_store",
        "name": "feature_2",
        "class": "org.apache.solr.ltr.feature.ValueFeature",
        "params": {
            "value": "${feature_2}",
            "required": false
        }
    },
....

Here “store” is the name of the feature store in the feature-store. It will be visible, after the upload, in the feature-store list.

Delete

To delete a feature store called first_store from the collection1 collection:

curl -XDELETE "https://localhost:8983/solr/collection1/schema/feature-store/first_store"

Learning to rank model store

List

As mentioned before:
A model uses features from only one feature store.
A feature store can be used by many models.
The list of the available models in the collection1 collection, is at:

https://localhost:8983/solr/collection1/schema/model-store

And it is something like:

{
  "responseHeader":{
    "status":0,
    "QTime":188},
  "models":[{
      "name":"model_1",
      "class":"org.apache.solr.ltr.model.MultipleAdditiveTreesModel",
      "store":"first_store",
      "features":[{
          "name":"feature_1",
          "norm":{"class":"org.apache.solr.ltr.norm.IdentityNormalizer"}},
        {
          "name":"feature_2",
          "norm":{"class":"org.apache.solr.ltr.norm.IdentityNormalizer"}},
....
      },
      {
      "name":"model_2",
      "class":"org.apache.solr.ltr.model.MultipleAdditiveTreesModel",
      "store":"first_store",
      "features":[{
          "name":"feature_1",
          "norm":{"class":"org.apache.solr.ltr.norm.IdentityNormalizer"}},
        {
          "name":"feature_3",
          "norm":{"class":"org.apache.solr.ltr.norm.IdentityNormalizer"}},
....

Here “name” is the name of the model in the model-store. It will be visible, after the upload, in the model-store list.

Upload

To upload a model to a model-store of a specific collection, we use the curl command:

curl -XPUT "https://localhost:8983/solr/collection1/schema/model-store" --data-binary "@solr-model.json" -H "Content-type:application/json"

Where solr-model.json is the file containing the model we want to upload.

For example:

{
    "store": "first_store",
    "name": "model_1",
    "class": "org.apache.solr.ltr.model.MultipleAdditiveTreesModel",
    "features": [
        {
            "name": "feature_1"
        },
        {
            "name": "feature_2"
        },
        {
            "name": "feature_3"
        },
....

Delete

To delete a model called model_1 from the collection1 collection:

curl -XDELETE "https://localhost:8983/solr/collection1/schema/model-store/model_1"

Reload

To reload the collection1 collection:

https://localhost:8983/solr/admin/collections?action=RELOAD&name=collection1&wt=xml

Warning

In using these methods we can run into some errors.

Don’t lose the next post to be sure to correctly use every method!