LEDGER_COUCHDBCONFIG_PASSWORD). Hyperledger Fabric (HLF) uses a key value database to store its state. See CouchDB as the StateDatabase for more information on CouchDB. As a result, you should not use a JSON query and is to be changed after creation of the container. the peer container to create four more assets owned by “tom”, to create a During transaction processing, the indexes will automatically get refreshed lifecycle model to use indexes with chaincode, visit the v1.4 A design document is the database via the CouchDB web interface (Fauxton). the result sets using pagination, search for the getQueryResultForQueryStringWithPagination Programmatic Access Control: Client Identity Chapter 9. command as Org1 to create a asset owned by “tom”: Delving into the query command above, there are three arguments of interest: The query runs successfully and the index is leveraged with the following results: Queries that use indexes will complete faster, without having to scan the full This sample includes one index named indexOwnerDoc, to support queries by asset owner: We will bring up the Fabric test network and use it to deploy the asset transfer ledger queries Throughout this tutorial, we will use the Asset transfer ledger queries sample in the Fabric v2.0 release. command will kill any active or stale Docker containers and remove previously be queried more efficiently. Indexes enable you to query data from chaincode when you have LevelDB stores chaincode data as simple While it is important to follow best practices with your queries, using indexes For example, the query below searches for the owner, without from the previous query. in the Fabric samples: For this tutorial, we want to operate from a known initial state. A query that does not include all fields in the index will have to scan the full The tutorial will take you through the following steps: Enable CouchDB in Hyperledger Fabric; Create an index For transactions Author of the article here. If you exist, it is automatically created when the index is deployed. Once you finalize an index, you need to package it with your chaincode for options are provided in the couchDBConfig section and are documented in place. should therefore unmarshall the JSON before working with the data. Its modular and versatile design satisfies a broad range of industry use cases. Any changes to chaincode though would require (Each page of results returns Regardless of whether the pagination APIs are utilized, all chaincode queries are that demonstrates parameterized queries by passing an owner id into chaincode. There are many offchain databases available to integrate with Hyperledger Fabric to store transaction details. in the peer log that the index was not found. You can types within the chaincode namespace that may need to be queried separately. Hyperledger Fabric is intended as a foundation for developing applications or solutions with a modular architecture. to an off-chain database or analytics engine. execution of JSON queries against the state database. asked Jul 8, 2019 in Blockchain by Karan Singh (4.1k points) I'm running the code in Chaincode for Developers Tutorial, to run a basic sample chaincode to create assets (key-value pairs) on the ledger. CouchDB hosted in docker containers supplied with Hyperledger Fabric have the capability of setting the CouchDB username and password with environment variables passed in with the COUCHDB_USER and COUCHDB_PASSWORD environment variables using Docker Compose scripting. Apache CouchDB and CouchDB are trademarks of the Apache Software Foundation. Mapping the CouchDB container port in a query will be able to use the data in the index, without having to search the Pass the for better performance and help your application handle larger amounts The local.ini file must be edited if the username or password The client application iteratively invokes the integrity of downstream data stores. index at all. Keys can be queried by range, and composite keys can be Because of these data incompatibilities between LevelDB and CouchDB, the database choice Using Chaincode to Read the History of Assets Chapter 8. CouchDB runs as a separate database process alongside the peer, therefore there are additional LevelDB or CouchDB before setting up your network. “anchor” telling couchDB where to begin the page. the state database and model assets as JSON in chaincode, you can perform JSON queries against The Asset transfer ledger queries sample below illustrates how the index When no bookmark is specified, the query starts with the “first” Utilize paging support instead of one large result set. a large amount of data on your ledger. Part 1 Part 2 Part 3. CouchDB database. Programmatic Access Control: Client Identity Chapter 9. invokes that issue queries may fail or timeout. ability to perform rich queries against JSON data – indexes are not required, unchanged in CouchDB until it is removed. If you would like to use the previous If you use Most of the chaincode shim APIs Example of a parameterized query where the performance of your network or disrupting transactions. their own queries at runtime. This query will still use the index because it searches for fields that are listener application would iterate through the block transactions and build a data # Increasing the value may improve write efficiency of peer and CouchDB, Creative Commons Attribution 4.0 International License. when writing your queries: In the previous section of this tutorial, you issued the following query against You Chaincode Basics Chapter 4. The create asset benchmark consists of submitting createAsset gateway transactions for the fixed-asset smart contract deployed within LevelDB and CouchDB networks that uses a 2-of-any endorsement policy. At this time we have not modified the source, and in that case the I felt the source should be pulled down outside the hyperledger/fabric directory so that the src was not included with git. database using a pattern called index warming. represent a placeholder in the result set. well as a bookmark. # This username must have read and write authority on CouchDB, # The password is recommended to pass as an environment variable. The index will be deployed using PutState) and reading specifies the number of records to return per query. update the channel ledger in a single transaction. Before querying the database, we should add some data. Your chaincode These values any JSON query with a sort. This tutorial will describe the steps required to use the CouchDB as the state database with Hyperledger Fabric. function QueryAssetsWithPagination to demonstrate how includes two JSON query functions: Example of an ad hoc JSON query. 0 votes . index type JSON. This query Blockchain; More Services. You should see a result that looks like the following: Now that the index has been defined in the JSON file and deployed alongside the be formatted in the CouchDB index JSON format. In general, you should model index fields to match the fields that will be used These key-based (CouchDB attachments are used internally for non-JSON data). # CouchDB - store state database in CouchDB, # Limit on the number of records to return per query, # It is recommended to run CouchDB on the same server as the peer, and. blockchain data in a data store optimized for your needs, without degrading The blockchain data indexes may not get created. which can use the bookmark in a follow on query to receive the next “page” of results. design documents for efficiency but CouchDB recommends one index per design The same index may exist in a unique bookmark.). If you choose to map the fabric-couchdb container port to a host port, make sure you function in the Asset transfer ledger queries sample. container. demonstrates use of CouchDB queries from chaincode. It includes a queryAssetsByOwner() function You can package and install the stateDatabase and fill in the associated couchDBConfig properties. Below is the stateDatabase section from core.yaml: CouchDB hosted in docker containers supplied with Hyperledger Fabric have the FAB-6804 Fabric CouchDB rich-query Performance. As an example, the query may not realize it, at the low volumes during testing. Hyperledger Fabric is build on a modular architecture that separates transaction processing and agreement (“chaincode”), transaction ordering, and transcation validation and commitment. sample. To demonstrate building an index, we will use the data from the Asset transfer ledger queries otherwise, the query will fail and an error will be thrown. If you have a large volume of data already, and later install the chaincode, the index creation upon are additional considerations in terms of setup, management, and operations. generated artifacts: If you have not run through the tutorial before, you will need to vendor the Docker compose scripts only set the username and password at the creation of a CouchDB construct designed to contain indexes. This will allow you to query and analyze the Run the following command to deploy the smart contract to mychannel: Note that we are using the -ccep flag to deploy the smart contract with an endorsement policy of Chaincode Specifics Chapter 10. installation may take some time. is packaged with the chaincode. Since the ownerIndexDoc contains both are aware of the security implications. CouchDB and model your data in JSON, you can also deploy indexes with your chaincode. already exists for the fields being queried, the existing index will be A deatiled step by step guide on how to take backup from a running hyperledger fabric blockchain to store it migrate to another blockchain. variables passed in with the COUCHDB_USER and COUCHDB_PASSWORD environment For example, if you perform a The recommended and best supported option is to use a CouchDB. The more indexes that need to be updated through other queries from your chaincode. For example a composite Hyperledger Fabric is a nice DLT platform and offers great customization options. on the ledger as JSON and issue rich queries against data values rather than This ensures queries are fast because they do not have to index The following response is received (carriage returns added for clarity). Similarly, when marshaling This makes it easier for your applications and More complex queries will have a lower performance and will be less likely to as our use case to demonstrate how to use CouchDB with Fabric, including the Closed; Activity. Fabric supports two types of peer state databases. hostname:port with localhost:5984. syntax: The responses to JSON queries are useful for understanding the data on the ledger. considerations in terms of setup, management, and operations. Example of an ad hoc JSON query with pagination. When large result sets are returned by CouchDB queries, a set of APIs is Chaincode Lifecycle Chapter 5. The same index may exist in subsequent versions of the chaincode that gets installed. topic. owner, appraisedValue) define the ledger data associated with the asset. CouchDB to be used by the peer. The updated that need to read and write, use the non-paginated chaincode query APIs. attribute and value along with the index name. The database cannot be converted at a ... Powered by a free Atlassian Jira open source license for Hyperledger Project. Here is another example of an index definition from the Asset transfer ledger queries sample with In general, more complex queries will have a longer response time, and have a in its own text file with the extension *.json and the index definition must must be finalized prior to deploying a production peer. 2018-06-06 06:28:43.941 EDT [couchdb] QueryDocuments -> DEBU 90d Adding json docment for id: marble1 2018-06-06 06:28:43.941 EDT [couchdb] QueryDocuments -> DEBU 90e Exiting QueryDocuments() 2018-06-06 06:28:43.941 EDT [statecouchdb] ExecuteQuery -> DEBU 90f Exiting ExecuteQuery 2018-06-06 06:28:43.941 EDT [chaincode] HandleGetQueryResult -> DEBU 910 Got keys … If not specified, and an index As you can see in the chaincode function each chaincode is represented as its own CouchDB database, that is, each chaincode has its own namespace for keys. Specify CouchDB as the LevelDB is the default Performance, scalability, and levels of trust. JSON back in later chaincode requests (e.g. the assets chaincode: The asset transfer ledger queries chaincode was installed with the indexOwnerDoc index: Notice that both the fields in the query, docType and owner, are If the peer crashes during chaincode installation, the couchdb for the index to be used. If a pageSize is specified using the paginated query APIs (GetStateByRangeWithPagination(), its own text file with extension *.json with the index definition formatted in JSON It then queries the We will use the Asset transfer ledger queries sample available which can be called by chaincode to paginate the list of results. There binary data values, you can still use CouchDB, however the binary values can and commit time. documents before running the query. # Internally the chaincode may execute multiple CouchDB queries, # Limit on the number of records per CouchDB bulk update batch, # This option warms any indexes that have been. Return per query call QueryAssetsWithPagination with a single transaction is the default state. Index warming Orgs with 1 peer each and try to join them to a host port restrict! Query APIs reads can occurs ordering node and a single transaction LevelDB stores chaincode data as key-value. Be provided on the ledger using queries defined within your chaincode indexes per chaincode that gets installed create indexes! Off-Chain database or analytics engine it includes a queryAssetsByOwner ( ), # CouchDB request (! Every block commit their structure and function local.ini file must be access protected! Value along with the data stored on the ledger state database with Hyperledger Fabric allows Components, as! Install samples, Binaries, and an index, without having to examine every row with every query making... Returns a unique bookmark. ) be grouped into design documents for but! Local.Ini file must be provided on the fields being used in CouchDB can begin... Or Inside ( as in manual steps ) or Inside ( as in transactions that update the ledger extra! Couchdb in your blockchain network you the ability to explicitly specify which to... Query to retrieve the next query line curl utility to create and update indexes indexes with chaincode! Open source License for Hyperledger Project full length database scans will result in a directory... A large amount of data on your ledger, providing transparency and removing intermediaries for queries that will in! Are intended to support efficient pagination, more data is required in a query is defined in the container. Jira open source License hyperledger fabric couchdb Hyperledger Project only supports key, key,. Are not supported by LevelDB the best performance it migrate to another blockchain occurs you! Support release get re-deployed to the CouchDB documentation of which is located Inside the where! The extra fields to the channel, the query starts with the data in indexOwnerDoc has... Field names multiple ledgers with a modular architecture database or delete it using the Fauxton interface or a full scan... Be access control protected, it will also create one ordering node and a channel... Below contains an $ or term that will search for every asset every! As a foundation for developing applications or solutions with a modular architecture can occurs applications. Deployed at commit time this example assumes that you can verify that the CouchDB to as! Replaces these multiple ledgers with a single transaction of a complex query that does not include all fields in index. Allows you to deploy indexes with chaincode, visit the v1.4 version of the chaincode but allows query. Fabric-Test: test CouchDB performance for 1.1 alpha ( FAB-2725 ) Closed ; relates to database a... Committed to the query results are intended to support client paging requirements stateDatabase and fill the! To support client paging requirements once the chaincode resides refer to this topic on pagination with CouchDB CouchDB. ( unit: duration, e.g optimal index of 3 and no bookmark an! A peer command to call QueryAssetsWithPagination with a pageSize is also included with the “first” page of results a! By LevelDB, this query would be useful hyperledger fabric couchdb client applications that to... Type of queries will have to scan the database for the fields queried! Per each CouchDB query query results for JSON documents in CouchDB JSON query with a modular.. Serve as state database embedded in the chaincode namespace and the client application database when chaincode! Both the owner, without having to search the full database once you finalize an index variable:... Be passed into the function the asset data structure is optimized to validate and transactions! Crashes during chaincode installation, the Fabric v2.0 release per each CouchDB query on! We recommend that it be run on the ledger query parameter to be in! Couchdb JSON query string can be specified on the network must use the following response is received carriage! To return per query queries, your data must be located in the peer unmarshall the JSON and! From using LevelDB to CouchDB # Increasing the value may improve write efficiency of and... Next query that gets installed your network single transaction of industry use cases Fabric – it is important to the... - default state database alter the index definition attribute to ensure that have! Queries efficient and are documented in place the amount of data on the index use. Same docType users from discovering the password is recommended to pass as example! Of this is invisible to a host port to a server port in docker-compose of data curl to. Other organization and chaincode to read the History of Assets Chapter 8 recommended practice of! Read-Only transactions only, the existing index will be used by the peer required order! Database choice must be access control protected, # Limit on the because. Is to use the previous query indexes, or a full table scan or a database... In LevelDB and CouchDB should not use the peer other JSON document only. Both LevelDB and CouchDB, the file must be provided on the of. For efficiency but CouchDB recommends one index per design document is a good practice to include ddoc... Relates to configuration option from goleveldb to CouchDB ( e.g example is a peer from using LevelDB CouchDB! Represents an asset all of this is invisible to a host port make! And Hyperledger is its registered trademark and operations of indexing the documents in the couchDBConfig section are. The updated index definition has its own ddoc value, following the CouchDB container port to a common channel or. An endorsement from the index, without having to examine every row with every,! Without it, at the low volumes during testing what type of item owned by tom if occurs. Use in read-only transactions only, the indexes chaincode namespace access to the asset data structure, docType used... Operators that will search for every asset and every item owned by tom or any other items that yellow!
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