| = Getting Started |
| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you under the Apache License, Version 2.0 (the |
| // "License"); you may not use this file except in compliance |
| // with the License. You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, |
| // software distributed under the License is distributed on an |
| // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| // KIND, either express or implied. See the License for the |
| // specific language governing permissions and limitations |
| // under the License. |
| |
| == Language |
| |
| *Streaming expressions* and *math expressions* are function languages that run |
| inside SolrCloud. The languages consist of functions |
| that are designed to be *composed* to form programming logic. |
| |
| *Streaming expressions* are functions that return streams of tuples. Streaming expression functions can be composed to form a transformation pipeline. |
| The pipeline starts with a *stream source*, such as `search`, which initiates a stream of tuples. |
| One or more *stream decorators*, such as `select`, wraps the stream source and transforms the stream of tuples. |
| |
| *Math expressions* are functions that operate over and return primitives and in-memory |
| arrays and matrices. The core use case for math expressions is performing mathematical operations and |
| visualization. |
| |
| Streaming expressions and math expressions can be combined to *search, |
| sample, aggregate, transform, analyze* and *visualize* data in SolrCloud collections. |
| |
| |
| == Execution |
| |
| Solr's `/stream` request handler executes streaming expressions and math expressions. |
| This handler compiles the expression, runs the expression logic |
| and returns a JSON result. |
| |
| === Admin UI Stream Panel |
| |
| The easiest way to run streaming expressions and math expressions is through |
| the *stream* panel on the Solr Admin UI. |
| |
| A sample `search` streaming expression is shown in the screenshot below: |
| |
| image::images/math-expressions/search.png[] |
| |
| A sample `add` math expression is shown in the screenshot below: |
| |
| image::images/math-expressions/add.png[] |
| |
| === Curl Example |
| |
| The HTTP interface to the `/stream` handler can be used to |
| send a streaming expression request and retrieve the response. |
| |
| Curl is a useful tool for running streaming expressions when the result |
| needs to be spooled to disk or is too large for the Solr admin stream panel. Below |
| is an example of a curl command to the `/stream` handler. |
| |
| [source,bash] |
| ---- |
| curl --data-urlencode 'expr=search(enron_emails, |
| q="from:1800flowers*", |
| fl="from, to", |
| sort="from asc")' http://localhost:8983/solr/enron_emails/stream |
| |
| ---- |
| |
| The JSON response from the stream handler for this request is shown below: |
| |
| [source,json] |
| ---- |
| {"result-set":{"docs":[ |
| {"from":"1800flowers.133139412@s2u2.com","to":"lcampbel@enron.com"}, |
| {"from":"1800flowers.93690065@s2u2.com","to":"jtholt@ect.enron.com"}, |
| {"from":"1800flowers.96749439@s2u2.com","to":"alewis@enron.com"}, |
| {"from":"1800flowers@1800flowers.flonetwork.com","to":"lcampbel@enron.com"}, |
| {"from":"1800flowers@1800flowers.flonetwork.com","to":"lcampbel@enron.com"}, |
| {"from":"1800flowers@1800flowers.flonetwork.com","to":"lcampbel@enron.com"}, |
| {"from":"1800flowers@1800flowers.flonetwork.com","to":"lcampbel@enron.com"}, |
| {"from":"1800flowers@1800flowers.flonetwork.com","to":"lcampbel@enron.com"}, |
| {"from":"1800flowers@shop2u.com","to":"ebass@enron.com"}, |
| {"from":"1800flowers@shop2u.com","to":"lcampbel@enron.com"}, |
| {"from":"1800flowers@shop2u.com","to":"lcampbel@enron.com"}, |
| {"from":"1800flowers@shop2u.com","to":"lcampbel@enron.com"}, |
| {"from":"1800flowers@shop2u.com","to":"ebass@enron.com"}, |
| {"from":"1800flowers@shop2u.com","to":"ebass@enron.com"}, |
| {"EOF":true,"RESPONSE_TIME":33}]} |
| } |
| ---- |
| |
| == Visualization |
| |
| The visualizations in this guide were performed with Apache Zeppelin using the |
| Zeppelin-Solr interpreter. |
| |
| === Zeppelin-Solr Interpreter |
| |
| An Apache Zeppelin interpreter for Solr allows streaming expressions and math expressions to be executed and results visualized in Zeppelin. |
| The instructions for installing and configuring Zeppelin-Solr can be found on the Github repository for the project: |
| https://github.com/lucidworks/zeppelin-solr |
| |
| Once installed the Solr Interpreter can be configured to connect to your Solr instance. |
| The screenshot below shows the panel for configuring Zeppelin-Solr. |
| |
| image::images/math-expressions/zepconf.png[] |
| |
| Configure the `solr.baseUrl` and `solr.collection` to point to the location where the streaming |
| expressions and math expressions will be sent for execution. The `solr.collection` is |
| just the execution collection and does not need to hold data, although it can hold data. |
| streaming expressions can choose to query any of the collections that are attached |
| to the same SolrCloud as the execution collection. |
| |
| === zplot |
| |
| Streaming expression result sets can be visualized automatically by Zeppelin-Solr. |
| |
| Math expression results need to be formatted for visualization using the `zplot` function. |
| This function has support for plotting *vectors*, *matrices*, *probability distributions* and |
| *2D clustering results*. |
| |
| There are many examples in the guide which show how to visualize both streaming expressions |
| and math expressions. |