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Java

tigerbeetle-java

The TigerBeetle client for Java.

javadoc

maven-central

Prerequisites

Linux >= 5.6 is the only production environment we support. But for ease of development we also support macOS and Windows.

  • Java >= 11
  • Maven >= 3.6 (not strictly necessary but it's what our guides assume)

Setup

First, create a directory for your project and cd into the directory.

Then create pom.xml and copy this into it:

<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.tigerbeetle</groupId>
  <artifactId>samples</artifactId>
  <version>1.0-SNAPSHOT</version>

  <properties>
    <maven.compiler.source>11</maven.compiler.source>
    <maven.compiler.target>11</maven.compiler.target>
  </properties>

  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.8.1</version>
        <configuration>
          <compilerArgs>
            <arg>-Xlint:all,-options,-path</arg>
          </compilerArgs>
        </configuration>
      </plugin>

      <plugin>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>exec-maven-plugin</artifactId>
        <version>1.6.0</version>
        <configuration>
          <mainClass>com.tigerbeetle.samples.Main</mainClass>
        </configuration>
      </plugin>
    </plugins>
  </build>

  <dependencies>
    <dependency>
      <groupId>com.tigerbeetle</groupId>
      <artifactId>tigerbeetle-java</artifactId>
      <!-- Grab the latest commit from: https://repo1.maven.org/maven2/com/tigerbeetle/tigerbeetle-java/maven-metadata.xml -->
      <version>0.0.1-3431</version>
    </dependency>
  </dependencies>
</project>

Then, install the TigerBeetle client:

mvn install

Now, create src/main/java/Main.java and copy this into it:

import com.tigerbeetle.*;

public final class Main {
    public static void main(String[] args) throws Exception {
        System.out.println("Import ok!");
    }
}

Finally, build and run:

mvn exec:java

Now that all prerequisites and dependencies are correctly set up, let's dig into using TigerBeetle.

Sample projects

This document is primarily a reference guide to the client. Below are various sample projects demonstrating features of TigerBeetle.

  • Basic: Create two accounts and transfer an amount between them.
  • Two-Phase Transfer: Create two accounts and start a pending transfer between them, then post the transfer.
  • Many Two-Phase Transfers: Create two accounts and start a number of pending transfer between them, posting and voiding alternating transfers.

Creating a Client

A client is created with a cluster ID and replica addresses for all replicas in the cluster. The cluster ID and replica addresses are both chosen by the system that starts the TigerBeetle cluster.

Clients are thread-safe and a single instance should be shared between multiple concurrent tasks.

Multiple clients are useful when connecting to more than one TigerBeetle cluster.

In this example the cluster ID is 0 and there is one replica. The address is read from the TB_ADDRESS environment variable and defaults to port 3000.

String replicaAddress = System.getenv("TB_ADDRESS");
byte[] clusterID = UInt128.asBytes(0);
String[] replicaAddresses = new String[] {replicaAddress == null ? "3000" : replicaAddress};
try (var client = new Client(clusterID, replicaAddresses)) {
    // Use client
}

The following are valid addresses:

  • 3000 (interpreted as 127.0.0.1:3000)
  • 127.0.0.1:3000 (interpreted as 127.0.0.1:3000)
  • 127.0.0.1 (interpreted as 127.0.0.1:3001, 3001 is the default port)

Creating Accounts

See details for account fields in the Accounts reference.

AccountBatch accounts = new AccountBatch(1);
accounts.add();
accounts.setId(UInt128.id()); // TigerBeetle time-based ID.
accounts.setUserData128(0, 0);
accounts.setUserData64(0);
accounts.setUserData32(0);
accounts.setLedger(1);
accounts.setCode(718);
accounts.setFlags(AccountFlags.NONE);
accounts.setTimestamp(0);

CreateAccountResultBatch accountErrors = client.createAccounts(accounts);
// Error handling omitted.

See details for the recommended ID scheme in time-based identifiers.

The 128-bit fields like id and user_data_128 have a few overrides to make it easier to integrate. You can either pass in a long, a pair of longs (least and most significant bits), or a byte[].

There is also a com.tigerbeetle.UInt128 helper with static methods for converting 128-bit little-endian unsigned integers between instances of long, java.util.UUID, java.math.BigInteger and byte[].

The fields for transfer amounts and account balances are also 128-bit, but they are always represented as a java.math.BigInteger.

Account Flags

The account flags value is a bitfield. See details for these flags in the Accounts reference.

To toggle behavior for an account, combine enum values stored in the AccountFlags object with bitwise-or:

  • AccountFlags.LINKED
  • AccountFlags.DEBITS_MUST_NOT_EXCEED_CREDITS
  • AccountFlags.CREDITS_MUST_NOT_EXCEED_CREDITS
  • AccountFlags.HISTORY

For example, to link two accounts where the first account additionally has the debits_must_not_exceed_credits constraint:

AccountBatch accounts = new AccountBatch(2);

accounts.add();
accounts.setId(100);
accounts.setLedger(1);
accounts.setCode(718);
accounts.setFlags(AccountFlags.LINKED | AccountFlags.DEBITS_MUST_NOT_EXCEED_CREDITS);

accounts.add();
accounts.setId(101);
accounts.setLedger(1);
accounts.setCode(718);
accounts.setFlags(AccountFlags.HISTORY);

CreateAccountResultBatch accountErrors = client.createAccounts(accounts);
// Error handling omitted.

Response and Errors

The response is an empty array if all accounts were created successfully. If the response is non-empty, each object in the response array contains error information for an account that failed. The error object contains an error code and the index of the account in the request batch.

See all error conditions in the create_accounts reference.

AccountBatch accounts = new AccountBatch(3);

accounts.add();
accounts.setId(102);
accounts.setLedger(1);
accounts.setCode(718);
accounts.setFlags(AccountFlags.NONE);

accounts.add();
accounts.setId(103);
accounts.setLedger(1);
accounts.setCode(718);
accounts.setFlags(AccountFlags.NONE);

accounts.add();
accounts.setId(104);
accounts.setLedger(1);
accounts.setCode(718);
accounts.setFlags(AccountFlags.NONE);

CreateAccountResultBatch accountErrors = client.createAccounts(accounts);
while (accountErrors.next()) {
    switch (accountErrors.getResult()) {
        case Exists:
            System.err.printf("Batch account at %d already exists.\n",
                    accountErrors.getIndex());
            break;

        default:
            System.err.printf("Batch account at %d failed to create %s.\n",
                    accountErrors.getIndex(), accountErrors.getResult());
            break;
    }
}

Account Lookup

Account lookup is batched, like account creation. Pass in all IDs to fetch. The account for each matched ID is returned.

If no account matches an ID, no object is returned for that account. So the order of accounts in the response is not necessarily the same as the order of IDs in the request. You can refer to the ID field in the response to distinguish accounts.

IdBatch ids = new IdBatch(2);
ids.add(100);
ids.add(101);

AccountBatch accounts = client.lookupAccounts(ids);

Create Transfers

This creates a journal entry between two accounts.

See details for transfer fields in the Transfers reference.

TransferBatch transfers = new TransferBatch(1);

transfers.add();
transfers.setId(UInt128.id());
transfers.setDebitAccountId(102);
transfers.setCreditAccountId(103);
transfers.setAmount(10);
transfers.setUserData128(0, 0);
transfers.setUserData64(0);
transfers.setUserData32(0);
transfers.setTimeout(0);
transfers.setLedger(1);
transfers.setCode(1);
transfers.setFlags(TransferFlags.NONE);
transfers.setTimeout(0);

CreateTransferResultBatch transferErrors = client.createTransfers(transfers);
// Error handling omitted.

See details for the recommended ID scheme in time-based identifiers.

Response and Errors

The response is an empty array if all transfers were created successfully. If the response is non-empty, each object in the response array contains error information for a transfer that failed. The error object contains an error code and the index of the transfer in the request batch.

See all error conditions in the create_transfers reference.

TransferBatch transfers = new TransferBatch(3);

transfers.add();
transfers.setId(1);
transfers.setDebitAccountId(102);
transfers.setCreditAccountId(103);
transfers.setAmount(10);
transfers.setLedger(1);
transfers.setCode(1);

transfers.add();
transfers.setId(2);
transfers.setDebitAccountId(102);
transfers.setCreditAccountId(103);
transfers.setAmount(10);
transfers.setLedger(1);
transfers.setCode(1);

transfers.add();
transfers.setId(3);
transfers.setDebitAccountId(102);
transfers.setCreditAccountId(103);
transfers.setAmount(10);
transfers.setLedger(1);
transfers.setCode(1);

CreateTransferResultBatch transferErrors = client.createTransfers(transfers);
while (transferErrors.next()) {
    switch (transferErrors.getResult()) {
        case ExceedsCredits:
            System.err.printf("Batch transfer at %d already exists.\n",
                    transferErrors.getIndex());
            break;

        default:
            System.err.printf("Batch transfer at %d failed to create: %s\n",
                    transferErrors.getIndex(), transferErrors.getResult());
            break;
    }
}

Batching

TigerBeetle performance is maximized when you batch API requests. The client does not do this automatically for you. So, for example, you can insert 1 million transfers one at a time like so:

ResultSet dataSource = null; /* Loaded from an external source. */;
while(dataSource.next()) {
    TransferBatch batch = new TransferBatch(1);

    batch.add();
    batch.setId(dataSource.getBytes("id"));
    batch.setDebitAccountId(dataSource.getBytes("debit_account_id"));
    batch.setCreditAccountId(dataSource.getBytes("credit_account_id"));
    batch.setAmount(dataSource.getBigDecimal("amount").toBigInteger());
    batch.setLedger(dataSource.getInt("ledger"));
    batch.setCode(dataSource.getInt("code"));

    CreateTransferResultBatch transferErrors = client.createTransfers(batch);
    // Error handling omitted.
}

But the insert rate will be a fraction of potential. Instead, always batch what you can.

The maximum batch size is set in the TigerBeetle server. The default is 8190.

ResultSet dataSource = null; /* Loaded from an external source. */;

var BATCH_SIZE = 8190;
TransferBatch batch = new TransferBatch(BATCH_SIZE);
while(dataSource.next()) {
    batch.add();
    batch.setId(dataSource.getBytes("id"));
    batch.setDebitAccountId(dataSource.getBytes("debit_account_id"));
    batch.setCreditAccountId(dataSource.getBytes("credit_account_id"));
    batch.setAmount(dataSource.getBigDecimal("amount").toBigInteger());
    batch.setLedger(dataSource.getInt("ledger"));
    batch.setCode(dataSource.getInt("code"));

    if (batch.getLength() == BATCH_SIZE) {
        CreateTransferResultBatch transferErrors = client.createTransfers(batch);
        // Error handling omitted.

        // Reset the batch for the next iteration.
        batch.beforeFirst();
    }
}

if (batch.getLength() > 0) {
    // Send the remaining items.
    CreateTransferResultBatch transferErrors = client.createTransfers(batch);
    // Error handling omitted.
}

Queues and Workers

If you are making requests to TigerBeetle from workers pulling jobs from a queue, you can batch requests to TigerBeetle by having the worker act on multiple jobs from the queue at once rather than one at a time. i.e. pulling multiple jobs from the queue rather than just one.

Transfer Flags

The transfer flags value is a bitfield. See details for these flags in the Transfers reference.

To toggle behavior for an account, combine enum values stored in the TransferFlags object with bitwise-or:

  • TransferFlags.NONE
  • TransferFlags.LINKED
  • TransferFlags.PENDING
  • TransferFlags.POST_PENDING_TRANSFER
  • TransferFlags.VOID_PENDING_TRANSFER

For example, to link transfer0 and transfer1:

TransferBatch transfers = new TransferBatch(2);

// First transfer
transfers.add();
transfers.setId(4);
transfers.setDebitAccountId(102);
transfers.setCreditAccountId(103);
transfers.setAmount(10);
transfers.setLedger(1);
transfers.setCode(1);
transfers.setFlags(TransferFlags.LINKED);

transfers.add();
transfers.setId(5);
transfers.setDebitAccountId(102);
transfers.setCreditAccountId(103);
transfers.setAmount(10);
transfers.setLedger(1);
transfers.setCode(1);
transfers.setFlags(TransferFlags.NONE);

CreateTransferResultBatch transferErrors = client.createTransfers(transfers);
// Error handling omitted.

Two-Phase Transfers

Two-phase transfers are supported natively by toggling the appropriate flag. TigerBeetle will then adjust the credits_pending and debits_pending fields of the appropriate accounts. A corresponding post pending transfer then needs to be sent to post or void the transfer.

Post a Pending Transfer

With flags set to post_pending_transfer, TigerBeetle will post the transfer. TigerBeetle will atomically roll back the changes to debits_pending and credits_pending of the appropriate accounts and apply them to the debits_posted and credits_posted balances.

TransferBatch transfers = new TransferBatch(1);

transfers.add();
transfers.setId(6);
transfers.setDebitAccountId(102);
transfers.setCreditAccountId(103);
transfers.setAmount(10);
transfers.setLedger(1);
transfers.setCode(1);
transfers.setFlags(TransferFlags.PENDING);

CreateTransferResultBatch transferErrors = client.createTransfers(transfers);
// Error handling omitted.

transfers = new TransferBatch(1);

transfers.add();
transfers.setId(7);
transfers.setAmount(TransferBatch.AMOUNT_MAX);
transfers.setPendingId(6);
transfers.setFlags(TransferFlags.POST_PENDING_TRANSFER);

transferErrors = client.createTransfers(transfers);
// Error handling omitted.

Void a Pending Transfer

In contrast, with flags set to void_pending_transfer, TigerBeetle will void the transfer. TigerBeetle will roll back the changes to debits_pending and credits_pending of the appropriate accounts and not apply them to the debits_posted and credits_posted balances.

TransferBatch transfers = new TransferBatch(1);

transfers.add();
transfers.setId(8);
transfers.setDebitAccountId(102);
transfers.setCreditAccountId(103);
transfers.setAmount(10);
transfers.setLedger(1);
transfers.setCode(1);
transfers.setFlags(TransferFlags.PENDING);

CreateTransferResultBatch transferErrors = client.createTransfers(transfers);
// Error handling omitted.

transfers = new TransferBatch(1);

transfers.add();
transfers.setId(9);
transfers.setAmount(0);
transfers.setPendingId(8);
transfers.setFlags(TransferFlags.VOID_PENDING_TRANSFER);

transferErrors = client.createTransfers(transfers);
// Error handling omitted.

Transfer Lookup

NOTE: While transfer lookup exists, it is not a flexible query API. We are developing query APIs and there will be new methods for querying transfers in the future.

Transfer lookup is batched, like transfer creation. Pass in all ids to fetch, and matched transfers are returned.

If no transfer matches an id, no object is returned for that transfer. So the order of transfers in the response is not necessarily the same as the order of ids in the request. You can refer to the id field in the response to distinguish transfers.

IdBatch ids = new IdBatch(2);
ids.add(1);
ids.add(2);

TransferBatch transfers = client.lookupTransfers(ids);

Get Account Transfers

NOTE: This is a preview API that is subject to breaking changes once we have a stable querying API.

Fetches the transfers involving a given account, allowing basic filter and pagination capabilities.

The transfers in the response are sorted by timestamp in chronological or reverse-chronological order.

AccountFilter filter = new AccountFilter();
filter.setAccountId(2);
filter.setUserData128(0); // No filter by UserData.
filter.setUserData64(0);
filter.setUserData32(0);
filter.setCode(0); // No filter by Code.
filter.setTimestampMin(0); // No filter by Timestamp.
filter.setTimestampMax(0); // No filter by Timestamp.
filter.setLimit(10); // Limit to ten transfers at most.
filter.setDebits(true); // Include transfer from the debit side.
filter.setCredits(true); // Include transfer from the credit side.
filter.setReversed(true); // Sort by timestamp in reverse-chronological order.

TransferBatch transfers = client.getAccountTransfers(filter);

Get Account Balances

NOTE: This is a preview API that is subject to breaking changes once we have a stable querying API.

Fetches the point-in-time balances of a given account, allowing basic filter and pagination capabilities.

Only accounts created with the flag history set retain historical balances.

The balances in the response are sorted by timestamp in chronological or reverse-chronological order.

AccountFilter filter = new AccountFilter();
filter.setAccountId(2);
filter.setUserData128(0); // No filter by UserData.
filter.setUserData64(0);
filter.setUserData32(0);
filter.setCode(0); // No filter by Code.
filter.setTimestampMin(0); // No filter by Timestamp.
filter.setTimestampMax(0); // No filter by Timestamp.
filter.setLimit(10); // Limit to ten balances at most.
filter.setDebits(true); // Include transfer from the debit side.
filter.setCredits(true); // Include transfer from the credit side.
filter.setReversed(true); // Sort by timestamp in reverse-chronological order.

AccountBalanceBatch account_balances = client.getAccountBalances(filter);

Query Accounts

NOTE: This is a preview API that is subject to breaking changes once we have a stable querying API.

Query accounts by the intersection of some fields and by timestamp range.

The accounts in the response are sorted by timestamp in chronological or reverse-chronological order.

QueryFilter filter = new QueryFilter();
filter.setUserData128(1000); // Filter by UserData.
filter.setUserData64(100);
filter.setUserData32(10);
filter.setCode(1); // Filter by Code.
filter.setLedger(0); // No filter by Ledger.
filter.setTimestampMin(0); // No filter by Timestamp.
filter.setTimestampMax(0); // No filter by Timestamp.
filter.setLimit(10); // Limit to ten balances at most.
filter.setReversed(true); // Sort by timestamp in reverse-chronological order.

AccountBatch accounts = client.queryAccounts(filter);

Query Transfers

NOTE: This is a preview API that is subject to breaking changes once we have a stable querying API.

Query transfers by the intersection of some fields and by timestamp range.

The transfers in the response are sorted by timestamp in chronological or reverse-chronological order.

QueryFilter filter = new QueryFilter();
filter.setUserData128(1000); // Filter by UserData.
filter.setUserData64(100);
filter.setUserData32(10);
filter.setCode(1); // Filter by Code.
filter.setLedger(0); // No filter by Ledger.
filter.setTimestampMin(0); // No filter by Timestamp.
filter.setTimestampMax(0); // No filter by Timestamp.
filter.setLimit(10); // Limit to ten balances at most.
filter.setReversed(true); // Sort by timestamp in reverse-chronological order.

TransferBatch transfers = client.queryTransfers(filter);

Linked Events

When the linked flag is specified for an account when creating accounts or a transfer when creating transfers, it links that event with the next event in the batch, to create a chain of events, of arbitrary length, which all succeed or fail together. The tail of a chain is denoted by the first event without this flag. The last event in a batch may therefore never have the linked flag set as this would leave a chain open-ended. Multiple chains or individual events may coexist within a batch to succeed or fail independently.

Events within a chain are executed within order, or are rolled back on error, so that the effect of each event in the chain is visible to the next, and so that the chain is either visible or invisible as a unit to subsequent events after the chain. The event that was the first to break the chain will have a unique error result. Other events in the chain will have their error result set to linked_event_failed.

TransferBatch transfers = new TransferBatch(10);

// An individual transfer (successful):
transfers.add();
transfers.setId(1);
// ... rest of transfer ...
transfers.setFlags(TransferFlags.NONE);

// A chain of 4 transfers (the last transfer in the chain closes the chain with
// linked=false):
transfers.add();
transfers.setId(2); // Commit/rollback.
// ... rest of transfer ...
transfers.setFlags(TransferFlags.LINKED);
transfers.add();
transfers.setId(3); // Commit/rollback.
// ... rest of transfer ...
transfers.setFlags(TransferFlags.LINKED);
transfers.add();
transfers.setId(2); // Fail with exists
// ... rest of transfer ...
transfers.setFlags(TransferFlags.LINKED);
transfers.add();
transfers.setId(4); // Fail without committing
// ... rest of transfer ...
transfers.setFlags(TransferFlags.NONE);

// An individual transfer (successful):
// This should not see any effect from the failed chain above.
transfers.add();
transfers.setId(2);
// ... rest of transfer ...
transfers.setFlags(TransferFlags.NONE);

// A chain of 2 transfers (the first transfer fails the chain):
transfers.add();
transfers.setId(2);
// ... rest of transfer ...
transfers.setFlags(TransferFlags.LINKED);
transfers.add();
transfers.setId(3);
// ... rest of transfer ...
transfers.setFlags(TransferFlags.NONE);
// A chain of 2 transfers (successful):
transfers.add();
transfers.setId(3);
// ... rest of transfer ...
transfers.setFlags(TransferFlags.LINKED);
transfers.add();
transfers.setId(4);
// ... rest of transfer ...
transfers.setFlags(TransferFlags.NONE);

CreateTransferResultBatch transferErrors = client.createTransfers(transfers);
// Error handling omitted.

Imported Events

When the imported flag is specified for an account when creating accounts or a transfer when creating transfers, it allows importing historical events with a user-defined timestamp.

The entire batch of events must be set with the flag imported.

It's recommended to submit the whole batch as a linked chain of events, ensuring that if any event fails, none of them are committed, preserving the last timestamp unchanged. This approach gives the application a chance to correct failed imported events, re-submitting the batch again with the same user-defined timestamps.

// External source of time
long historicalTimestamp = 0L;
ResultSet historicalAccounts = null; // Loaded from an external source;
ResultSet historicalTransfers = null ; // Loaded from an external source.

var BATCH_SIZE = 8190;

// First, load and import all accounts with their timestamps from the historical source.
AccountBatch accounts = new AccountBatch(BATCH_SIZE);
while (historicalAccounts.next()) {
    // Set a unique and strictly increasing timestamp.
    historicalTimestamp += 1;

    accounts.add();
    accounts.setId(historicalAccounts.getBytes("id"));
    accounts.setLedger(historicalAccounts.getInt("ledger"));
    accounts.setCode(historicalAccounts.getInt("code"));
    accounts.setTimestamp(historicalTimestamp);

    // Set the account as `imported`.
    // To ensure atomicity, the entire batch (except the last event in the chain)
    // must be `linked`.
    if (accounts.getLength() < BATCH_SIZE) {
        accounts.setFlags(AccountFlags.IMPORTED | AccountFlags.LINKED);
    } else {
        accounts.setFlags(AccountFlags.IMPORTED);

        CreateAccountResultBatch accountsErrors = client.createAccounts(accounts);
        // Error handling omitted.

        // Reset the batch for the next iteration.
        accounts.beforeFirst();
    }
}

if (accounts.getLength() > 0) {
    // Send the remaining items.
    CreateAccountResultBatch accountsErrors = client.createAccounts(accounts);
    // Error handling omitted.
}

// Then, load and import all transfers with their timestamps from the historical source.
TransferBatch transfers = new TransferBatch(BATCH_SIZE);
while (historicalTransfers.next()) {
    // Set a unique and strictly increasing timestamp.
    historicalTimestamp += 1;

    transfers.add();
    transfers.setId(historicalTransfers.getBytes("id"));
    transfers.setDebitAccountId(historicalTransfers.getBytes("debit_account_id"));
    transfers.setCreditAccountId(historicalTransfers.getBytes("credit_account_id"));
    transfers.setAmount(historicalTransfers.getBigDecimal("amount").toBigInteger());
    transfers.setLedger(historicalTransfers.getInt("ledger"));
    transfers.setCode(historicalTransfers.getInt("code"));
    transfers.setTimestamp(historicalTimestamp);

    // Set the transfer as `imported`.
    // To ensure atomicity, the entire batch (except the last event in the chain)
    // must be `linked`.
    if (transfers.getLength() < BATCH_SIZE) {
        transfers.setFlags(TransferFlags.IMPORTED | TransferFlags.LINKED);
    } else {
        transfers.setFlags(TransferFlags.IMPORTED);

        CreateTransferResultBatch transferErrors = client.createTransfers(transfers);
        // Error handling omitted.

        // Reset the batch for the next iteration.
        transfers.beforeFirst();
    }
}

if (transfers.getLength() > 0) {
    // Send the remaining items.
    CreateTransferResultBatch transferErrors = client.createTransfers(transfers);
    // Error handling omitted.
}

// Since it is a linked chain, in case of any error the entire batch is rolled back and can be retried
// with the same historical timestamps without regressing the cluster timestamp.