happner-elastic-dataprovider

happner elastic dataprovider

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

NB: still in active dev, so don't use in production yet.

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

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 } }