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Glossary

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Acquisition notice

In October 2022, ServiceNow acquired Era Software. The documentation on this site is no longer maintained and is intended for existing Era Software users only.

To get the latest information about ServiceNow's observability solutions, visit their website and documentation.

This page defines commonly used terms for Era Software products.

alert rule

Alert rules define when and where EraSearch sends alerts. You can create and edit alert rules based on your data and alerting needs.

Here's an example of an alert rule: If this query (code:404 AND method:GET) returns more than 5 results over the past 6 hours, send an alert to Slack.

Note

Only EraSearch on EraCloud supports alerting. Future self-hosted EraSearch releases will support alerting.

API Service

The API Service is one of EraSearch's four internal database services. This service receives and handles all client requests. You can run several API Service instances for scalability.

batch

A batch request is a write request issued to the database, which can include one or many documents.

Cache Service

The Cache Service is one of EraSearch's four internal database services. This service handles the in-database hot cache, including:

  • Writing data to local storage
  • Compacting data to maximize query performance
  • Servicing query results from local storage

You can run several Cache Service instances for scalability.

compaction

A compaction is when the database consolidates data on disk to optimize for read performance. Compactions include a "level", which is the number of times that the objects have been compacted together.

Coordinator Service

The Coordinator Service is one of EraSearch's four internal database services. This service generates and works with object IDs (OIDs). OIDs are unique identifiers that EraSearch uses to store and retrieve data. Coordinator Service stores OIDs in Redis.

document

A document is a JSON object made up of data. In EraSearch, all documents have a unique identifier (_id) and a timestamp (_ts). Most documents include additional fields. Here's an example of a document:

{"_id":4248176661010579457,"_line":"access","response":200,"_ts":1634060854000}

EraCloud

EraCloud is Era Software’s SaaS product, offering hosted EraSearch. As of October 2021, EraCloud supports Amazon Web Services only. Future releases will include Google Cloud Platform and Microsoft Azure.

EraSearch

EraSearch is Era Software’s petabyte-scale platform for log management. EraSearch has two main parts:

  • EraSearch database - A high-performance, cost-optimized, and scalable database
  • EraSearch UI - A UI for exploring and interacting with log data

Note

As of January 2022, only EraCloud comes with the EraSearch UI. Future self-hosted EraSearch releases will support the UI. Until then, self-hosted EraSearch users can use Grafana to visualize and interact with their data.

field

A field is data stored as a key and value pair.

index

An index is a group of similar documents. With EraSearch, you can query documents in one or more indexes to optimize your searches.

notification channel

Notification channels are applications that can receive EraSearch alerts. EraSearch supports these notification channels: Slack, and Webhooks.

Note

Only EraSearch on EraCloud supports alerting. Future self-hosted EraSearch releases will support alerting.

OID (Object ID)

A unique identifier given to every document stored within an EraSearch index. Each OID is composed of a sequence number and other internal metadata.

rehydration

Rehydration occurs when a Cache Service pod fetches data from object storage.

root

A root is how indexed data stored within EraSearch gets persisted to disk. Roots are similar in nature to "shards" used by Elasticsearch and other databases. Each batch request sent to the database creates a new root. Roots are then compacted over time to optimize for read performance.

rootset

A rootset is a set of files within a Cache Service pod that represent all of the ingested data (aka "roots") that the pod is aware of.

self-hosted EraSearch

What we call EraSearch when you run and manage EraSearch yourself on your own cloud infrastructure.

Storage Service

The Storage Service is one of EraSearch's four internal database services. The service optimizes communication with object storage (for example, S3 when running in AWS). It achieves high performance with minimal networking overhead.

sequence number

A sequence number is a unique, monotonically (always) increasing number. Sequence numbers are included within the internal OID structure, ensuring a unique number per document ingested. The Coordinator Service is responsible for generating sequence numbers.


Last update: August 7, 2023