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Elasticsearch

Overview

A MultiversX node can enable the indexing within an Elasticsearch instance. Indexed data will serve as historical data source that can be used as it is for searching purposes or to serve a front-end application.

tip

Due to the possible high data volume, it's not recommended to use validators as nodes to index in Elasticsearch from. Our implementation uses a concept of a queue and makes sure that everything is being processed. Consensus and synchronization mechanisms can have delays because of the indexing.

Setup

Option 1

Set up four observers, each corresponding to a shard, with the WebSocketHost enabled, and create an instance of the elasticindexer service. Follow the instructions provided on this page to accomplish this.

Option 2

danger

We plan to remove this option in the rc/v1.7.0 release.

In order to set up an observer that indexes in Elasticsearch, one has to update the external.toml file from the node's configuration directory. A minimum configuration would have Enabled set to true and the rest of the fields updated accordingly (URL, Username, Password).

An example of a configuration is:

# ElasticSearchConnector defines settings related to ElasticSearch such as login information or URL
[ElasticSearchConnector]
## We do not recommend to activate this indexer on a validator node since
#the node might loose rating (even facing penalties) due to the fact that
#the indexer is called synchronously and might block due to external causes.
#Strongly suggested to activate this on a regular observer node.
Enabled = true
IndexerCacheSize = 0
BulkRequestMaxSizeInBytes = 4194304 # 4MB
URL = "http://localhost:9200"
UseKibana = false
Username = "elastic-username"
Password = "elastic-password"
# EnabledIndexes represents a slice of indexes that will be enabled for indexing. Full list is:
# ["rating", "transactions", "blocks", "validators", "miniblocks", "rounds", "accounts", "accountshistory", "receipts", "scresults", "accountsesdt", "accountsesdthistory", "epochinfo", "scdeploys", "tokens", "tags", "logs", "delegators", "operations"]
EnabledIndexes = ["rating", "transactions", "blocks", "validators", "miniblocks", "rounds", "accounts", "accountshistory", "receipts", "scresults", "accountsesdt", "accountsesdthistory", "epochinfo", "scdeploys", "tokens", "tags", "logs", "delegators", "operations"]

Kibana can be used for visualizing Elastic Data. Kikana's path must be _plugin/kibana/api (as seen in AWS managed instances).

EnabledIndexes array specifies the indices that will be populated.

Proxy support

There are some endpoints in elrond-proxy that rely on an Elasticsearch instance. They can be found here.

Multi-shards

In order to have the history of the entire network, one has to enable elastic indexing for a node in each shard (0, 1, 2 and metachain). Some features that ensure data validity rely on the fact that a node of each shard indexes in the database. For example, the status of a cross-shard transaction is decided on the destination shard.

Elasticsearch cluster system requirements

The Elasticsearch cluster can be installed on multiple machines (we recommend a setup with more nodes in a cluster) or on a single one.

In case of a single machine, our recommendation is as follows:

  • 12 x CPU
  • 32 GB RAM
  • Disk space that can grow up to 3 TB
  • 100 Mbit/s always-on Internet connection

Clone an Elasticsearch cluster

In order to have all the information about the MultiversX chain in an Elasticsearch cluster (from genesis to current time) one has to copy all the data with a specific tool from an Elasticsearch cluster to another. To get more information how to do this use the documentation from this repository.

Elasticsearch indices

An observing-squad with the elastic indexer enabled will save data in different indices. This data is used for multiple use cases. An example is to fetch all the transactions that belong to an address or to display all the address sorted based on the EGLD balances.

Each entry in an Elasticsearch index will have a format similar to this:

{
"_id": "..."
"_source": {
...
}
}
NameDescription
transactionsContains all transactions.
blocksContains all executed blocks.
validatorsContains the public keys of the validators grouped by epoch and shard.
ratingContains the validators' rating for every epoch.
miniblocksContains all executed minblocks.
roundsContains details of each round that has passed.
accountsContains the addresses' balances and the timestamp when they were modified.
accountshistoryContains historical information about the address balances.
receiptsContains all generated receipts.
scresultsContains all generated smart contract results.
accountsesdtContains the addresses' ESDT balances.
accountsesdthistoryContains historical information about the address ESDT balances.
epochinfoContains the accumulated fees and the developer fees grouped by epochs.
scdeploysContains details about all the deployed smart contracts.
tokensContains all created ESDT tokens.
tagsContains the NFTs' tags.
logsContains all the logs generated by transactions and smart contract results.
delegatorsContains details about all the delegators.
operationsContains all transactions and smart contract results.

Troubleshooting