happn-db-provider-elasticsearch

happner elastic dataprovider

This dataprovider provides the ability to run happner/happn instances off of elasticsearch instead of mongo or nedb

supports elastic <= 6.4.0

installing elasticsearch and redis on your local machine:

# elastic search - version is 5.1.1
docker pull docker.elastic.co/elasticsearch/elasticsearch:5.1.1

docker run -p 9200:9200 \
    -p 9300:9300 \
    -e "xpack.security.enabled=false" \
    docker.elastic.co/elasticsearch/elasticsearch:5.1.1

# redis
docker pull redis

docker run -p 6379:6379 -d redis

installation instructions:

#install deps
npm install happner-elastic-dataprovider
#test run - most should pass
mocha test/func

#now run the historian data upload - this is demo code
node test/historian/server/start.js

Installing ElasticSearch and running ElasticSearch

curl -L -O https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-5.5.1-linux-x86_64.tar.gz
tar -xvf elasticsearch-5.5.1-linux-x86_64.tar.gz 
./elasticsearch-5.5.1/bin/elasticsearch

configuration:

//single use config - everything goes into elasticsearch
var config = {
  happn:{
    services:{
      data:{
        config:{
          datastores:[
            {
              name:'elastic',
              provider:'happner-elastic-dataprovider',
              settings:{"host":"localhost:9200"},
              isDefault:true
            }
          ]
        }
      }
    }
  }
};

//dual config, send all items starting with the path /history/ to elastic search, all others go to the default nedb instance
var config = {
  happn:{
    services:{
      data:{
        config:{
          datastores:[
            {
              name:'elastic',
              provider:'happner-elastic-dataprovider',
              settings:{"host":"localhost:9200"},
              patterns:["/history/*"]
            },
            {
              name:'happn',
              isDefault:true
            }
          ]
        }
      }
    }
  }
};

//then create happner instance as usual:

var Happner = require('happner');

Happner.create(config)

.then(function(mesh) {
// got running mesh
})

.catch(function(error) {
console.error(error.stack || error.toString())
process.exit(1);
});

Happner setup instructions in more detail here.

Supported Mongo Style Search Parameters

• $eq
• $gt
• $gte
• $in
• $lt
• $lte
• $ne
• $nin
• $and
• $not
• $nor
• $or
• $exists
• $regex

Limitations

sorting by a text field

var test_path = '/1_eventemitter_embedded_sanity/' +
    test_id +
    '/test subscribe/data/complex/' +
    require('shortid').generate();

var complex_obj = {
  regions: ['North', 'South'],
  towns: ['North.Cape Town'],
  categories: ['Action', 'History'],
  subcategories: ['Action.angling', 'History.art'],
  keywords: ['bass', 'Penny Siopis'],
  field1: 'field1'
};

var options1 = {
  sort: {
    'data.field1': 1 //unless you have set up the index mapping to make 'data.field1' a keyword, this search  will fail, see ./test/__fixtures/happn-config for a keyword mapping
  },
  limit: 1
};

await publisherclient.set(test_path, complex_obj);

// because we sorting by a text field this will be rejected, you can sort by dates and number type fields however
const results = await publisherclient.get(
  '/1_eventemitter_embedded_sanity/' + test_id + '/test subscribe/data/complex/*',
  {
    criteria: criteria1,
    options: options1
  }
);

Embedded documents

Embedded documents works slightly different than traditional mongo queries Consider the following document:

{ size:{ h: 14, w: 21, uom: "cm" } }

Field order does not matter for this provider while they matter for regular mongo. Given the following query, mongo would not match while this provider will.

{ size:{ w: 21, h: 14, uom: "cm" } }

When a document is specified as an query mongo requires the document to be a precise match. This provider only requires the specified fields to match. The following query will match using this provider but won't match using mongo

{ size:{ w: 21, h: 14 } }