Ingest nodes
As we learnt in the previous section, ingest nodes help to preprocess things before a document is indexed. Before a bulk request or index operations, the ingest node intercepts the request and does required processing on the document. An example of such a processor can be the date processor, which is used to parse the dates in fields. Another example is a convert processor, which converts a field value to a target type, for example, string to integer. A number of processors are available at: https://www.elastic.co/guide/en/elasticsearch/reference/5.1/ingest-processors.html.
These kinds of nodes are helpful when a huge processing happens and we do not want a data node or master node to engage in processing. Dedicated ingest nodes can help to reduce the load significantly. It is best to set node.ingest
as false
for data and master nodes.
To understand how ingest nodes work with pipelines, let's follow these steps. Let's take the example of our library
index and type...