Class: Aws::QLDBSession::Client

Seahorse::Client::Base show all
Defined in:


An API client for QLDBSession. To construct a client, you need to configure a :region and :credentials.

client =
  region: region_name,
  credentials: credentials,
  # ...

For details on configuring region and credentials see the developer guide.

See #initialize for a full list of supported configuration options.

Instance Attribute Summary

Attributes inherited from Seahorse::Client::Base

#config, #handlers

API Operations collapse

Instance Method Summary collapse

Methods included from ClientStubs

#api_requests, #stub_data, #stub_responses

Methods inherited from Seahorse::Client::Base

add_plugin, api, clear_plugins, define, new, #operation_names, plugins, remove_plugin, set_api, set_plugins

Methods included from Seahorse::Client::HandlerBuilder

#handle, #handle_request, #handle_response

Constructor Details

#initialize(options) ⇒ Client

Returns a new instance of Client.


  • options (Hash)

Options Hash (options):

  • :credentials (required, Aws::CredentialProvider)

    Your AWS credentials. This can be an instance of any one of the following classes:

    • Aws::Credentials - Used for configuring static, non-refreshing credentials.

    • Aws::SharedCredentials - Used for loading static credentials from a shared file, such as ~/.aws/config.

    • Aws::AssumeRoleCredentials - Used when you need to assume a role.

    • Aws::AssumeRoleWebIdentityCredentials - Used when you need to assume a role after providing credentials via the web.

    • Aws::SSOCredentials - Used for loading credentials from AWS SSO using an access token generated from aws login.

    • Aws::ProcessCredentials - Used for loading credentials from a process that outputs to stdout.

    • Aws::InstanceProfileCredentials - Used for loading credentials from an EC2 IMDS on an EC2 instance.

    • Aws::ECSCredentials - Used for loading credentials from instances running in ECS.

    • Aws::CognitoIdentityCredentials - Used for loading credentials from the Cognito Identity service.

    When :credentials are not configured directly, the following locations will be searched for credentials:

    • Aws.config[:credentials]
    • The :access_key_id, :secret_access_key, and :session_token options.
    • ~/.aws/credentials
    • ~/.aws/config
    • EC2/ECS IMDS instance profile - When used by default, the timeouts are very aggressive. Construct and pass an instance of Aws::InstanceProfileCredentails or Aws::ECSCredentials to enable retries and extended timeouts. Instance profile credential fetching can be disabled by setting ENV['AWS_EC2_METADATA_DISABLED'] to true.
  • :region (required, String)

    The AWS region to connect to. The configured :region is used to determine the service :endpoint. When not passed, a default :region is searched for in the following locations:

    • Aws.config[:region]
    • ~/.aws/credentials
    • ~/.aws/config
  • :access_key_id (String)
  • :active_endpoint_cache (Boolean) — default: false

    When set to true, a thread polling for endpoints will be running in the background every 60 secs (default). Defaults to false.

  • :adaptive_retry_wait_to_fill (Boolean) — default: true

    Used only in adaptive retry mode. When true, the request will sleep until there is sufficent client side capacity to retry the request. When false, the request will raise a RetryCapacityNotAvailableError and will not retry instead of sleeping.

  • :client_side_monitoring (Boolean) — default: false

    When true, client-side metrics will be collected for all API requests from this client.

  • :client_side_monitoring_client_id (String) — default: ""

    Allows you to provide an identifier for this client which will be attached to all generated client side metrics. Defaults to an empty string.

  • :client_side_monitoring_host (String) — default: ""

    Allows you to specify the DNS hostname or IPv4 or IPv6 address that the client side monitoring agent is running on, where client metrics will be published via UDP.

  • :client_side_monitoring_port (Integer) — default: 31000

    Required for publishing client metrics. The port that the client side monitoring agent is running on, where client metrics will be published via UDP.

  • :client_side_monitoring_publisher (Aws::ClientSideMonitoring::Publisher) — default: Aws::ClientSideMonitoring::Publisher

    Allows you to provide a custom client-side monitoring publisher class. By default, will use the Client Side Monitoring Agent Publisher.

  • :convert_params (Boolean) — default: true

    When true, an attempt is made to coerce request parameters into the required types.

  • :correct_clock_skew (Boolean) — default: true

    Used only in standard and adaptive retry modes. Specifies whether to apply a clock skew correction and retry requests with skewed client clocks.

  • :defaults_mode (String) — default: "legacy"

    See DefaultsModeConfiguration for a list of the accepted modes and the configuration defaults that are included.

  • :disable_host_prefix_injection (Boolean) — default: false

    Set to true to disable SDK automatically adding host prefix to default service endpoint when available.

  • :disable_request_compression (Boolean) — default: false

    When set to 'true' the request body will not be compressed for supported operations.

  • :endpoint (String)

    The client endpoint is normally constructed from the :region option. You should only configure an :endpoint when connecting to test or custom endpoints. This should be a valid HTTP(S) URI.

  • :endpoint_cache_max_entries (Integer) — default: 1000

    Used for the maximum size limit of the LRU cache storing endpoints data for endpoint discovery enabled operations. Defaults to 1000.

  • :endpoint_cache_max_threads (Integer) — default: 10

    Used for the maximum threads in use for polling endpoints to be cached, defaults to 10.

  • :endpoint_cache_poll_interval (Integer) — default: 60

    When :endpoint_discovery and :active_endpoint_cache is enabled, Use this option to config the time interval in seconds for making requests fetching endpoints information. Defaults to 60 sec.

  • :endpoint_discovery (Boolean) — default: false

    When set to true, endpoint discovery will be enabled for operations when available.

  • :ignore_configured_endpoint_urls (Boolean)

    Setting to true disables use of endpoint URLs provided via environment variables and the shared configuration file.

  • :log_formatter (Aws::Log::Formatter) — default: Aws::Log::Formatter.default

    The log formatter.

  • :log_level (Symbol) — default: :info

    The log level to send messages to the :logger at.

  • :logger (Logger)

    The Logger instance to send log messages to. If this option is not set, logging will be disabled.

  • :max_attempts (Integer) — default: 3

    An integer representing the maximum number attempts that will be made for a single request, including the initial attempt. For example, setting this value to 5 will result in a request being retried up to 4 times. Used in standard and adaptive retry modes.

  • :profile (String) — default: "default"

    Used when loading credentials from the shared credentials file at HOME/.aws/credentials. When not specified, 'default' is used.

  • :request_min_compression_size_bytes (Integer) — default: 10240

    The minimum size in bytes that triggers compression for request bodies. The value must be non-negative integer value between 0 and 10485780 bytes inclusive.

  • :retry_backoff (Proc)

    A proc or lambda used for backoff. Defaults to 2**retries * retry_base_delay. This option is only used in the legacy retry mode.

  • :retry_base_delay (Float) — default: 0.3

    The base delay in seconds used by the default backoff function. This option is only used in the legacy retry mode.

  • :retry_jitter (Symbol) — default: :none

    A delay randomiser function used by the default backoff function. Some predefined functions can be referenced by name - :none, :equal, :full, otherwise a Proc that takes and returns a number. This option is only used in the legacy retry mode.


  • :retry_limit (Integer) — default: 3

    The maximum number of times to retry failed requests. Only ~ 500 level server errors and certain ~ 400 level client errors are retried. Generally, these are throttling errors, data checksum errors, networking errors, timeout errors, auth errors, endpoint discovery, and errors from expired credentials. This option is only used in the legacy retry mode.

  • :retry_max_delay (Integer) — default: 0

    The maximum number of seconds to delay between retries (0 for no limit) used by the default backoff function. This option is only used in the legacy retry mode.

  • :retry_mode (String) — default: "legacy"

    Specifies which retry algorithm to use. Values are:

    • legacy - The pre-existing retry behavior. This is default value if no retry mode is provided.

    • standard - A standardized set of retry rules across the AWS SDKs. This includes support for retry quotas, which limit the number of unsuccessful retries a client can make.

    • adaptive - An experimental retry mode that includes all the functionality of standard mode along with automatic client side throttling. This is a provisional mode that may change behavior in the future.

  • :sdk_ua_app_id (String)

    A unique and opaque application ID that is appended to the User-Agent header as app/. It should have a maximum length of 50.

  • :secret_access_key (String)
  • :session_token (String)
  • :simple_json (Boolean) — default: false

    Disables request parameter conversion, validation, and formatting. Also disable response data type conversions. This option is useful when you want to ensure the highest level of performance by avoiding overhead of walking request parameters and response data structures.

    When :simple_json is enabled, the request parameters hash must be formatted exactly as the DynamoDB API expects.

  • :stub_responses (Boolean) — default: false

    Causes the client to return stubbed responses. By default fake responses are generated and returned. You can specify the response data to return or errors to raise by calling ClientStubs#stub_responses. See ClientStubs for more information.

    Please note When response stubbing is enabled, no HTTP requests are made, and retries are disabled.

  • :token_provider (Aws::TokenProvider)

    A Bearer Token Provider. This can be an instance of any one of the following classes:

    • Aws::StaticTokenProvider - Used for configuring static, non-refreshing tokens.

    • Aws::SSOTokenProvider - Used for loading tokens from AWS SSO using an access token generated from aws login.

    When :token_provider is not configured directly, the Aws::TokenProviderChain will be used to search for tokens configured for your profile in shared configuration files.

  • :use_dualstack_endpoint (Boolean)

    When set to true, dualstack enabled endpoints (with .aws TLD) will be used if available.

  • :use_fips_endpoint (Boolean)

    When set to true, fips compatible endpoints will be used if available. When a fips region is used, the region is normalized and this config is set to true.

  • :validate_params (Boolean) — default: true

    When true, request parameters are validated before sending the request.

  • :endpoint_provider (Aws::QLDBSession::EndpointProvider)

    The endpoint provider used to resolve endpoints. Any object that responds to #resolve_endpoint(parameters) where parameters is a Struct similar to Aws::QLDBSession::EndpointParameters

  • :http_proxy (URI::HTTP, String)

    A proxy to send requests through. Formatted like ''.

  • :http_open_timeout (Float) — default: 15

    The number of seconds to wait when opening a HTTP session before raising a Timeout::Error.

  • :http_read_timeout (Float) — default: 60

    The default number of seconds to wait for response data. This value can safely be set per-request on the session.

  • :http_idle_timeout (Float) — default: 5

    The number of seconds a connection is allowed to sit idle before it is considered stale. Stale connections are closed and removed from the pool before making a request.

  • :http_continue_timeout (Float) — default: 1

    The number of seconds to wait for a 100-continue response before sending the request body. This option has no effect unless the request has "Expect" header set to "100-continue". Defaults to nil which disables this behaviour. This value can safely be set per request on the session.

  • :ssl_timeout (Float) — default: nil

    Sets the SSL timeout in seconds.

  • :http_wire_trace (Boolean) — default: false

    When true, HTTP debug output will be sent to the :logger.

  • :ssl_verify_peer (Boolean) — default: true

    When true, SSL peer certificates are verified when establishing a connection.

  • :ssl_ca_bundle (String)

    Full path to the SSL certificate authority bundle file that should be used when verifying peer certificates. If you do not pass :ssl_ca_bundle or :ssl_ca_directory the the system default will be used if available.

  • :ssl_ca_directory (String)

    Full path of the directory that contains the unbundled SSL certificate authority files for verifying peer certificates. If you do not pass :ssl_ca_bundle or :ssl_ca_directory the the system default will be used if available.

# File 'gems/aws-sdk-qldbsession/lib/aws-sdk-qldbsession/client.rb', line 395

def initialize(*args)

Instance Method Details

#send_command(params = {}) ⇒ Types::SendCommandResult

Sends a command to an Amazon QLDB ledger.

Instead of interacting directly with this API, we recommend using the QLDB driver or the QLDB shell to execute data transactions on a ledger.

  • If you are working with an AWS SDK, use the QLDB driver. The driver provides a high-level abstraction layer above this QLDB Session data plane and manages SendCommand API calls for you. For information and a list of supported programming languages, see Getting started with the driver in the Amazon QLDB Developer Guide.

  • If you are working with the AWS Command Line Interface (AWS CLI), use the QLDB shell. The shell is a command line interface that uses the QLDB driver to interact with a ledger. For information, see Accessing Amazon QLDB using the QLDB shell.


Request syntax with placeholder values

resp = client.send_command({
  session_token: "SessionToken",
  start_session: {
    ledger_name: "LedgerName", # required
  start_transaction: {
  end_session: {
  commit_transaction: {
    transaction_id: "TransactionId", # required
    commit_digest: "data", # required
  abort_transaction: {
  execute_statement: {
    transaction_id: "TransactionId", # required
    statement: "Statement", # required
    parameters: [
        ion_binary: "data",
        ion_text: "IonText",
  fetch_page: {
    transaction_id: "TransactionId", # required
    next_page_token: "PageToken", # required

Response structure

resp.start_session.session_token #=> String
resp.start_session.timing_information.processing_time_milliseconds #=> Integer
resp.start_transaction.transaction_id #=> String
resp.start_transaction.timing_information.processing_time_milliseconds #=> Integer
resp.end_session.timing_information.processing_time_milliseconds #=> Integer
resp.commit_transaction.transaction_id #=> String
resp.commit_transaction.commit_digest #=> String
resp.commit_transaction.timing_information.processing_time_milliseconds #=> Integer
resp.commit_transaction.consumed_i_os.read_i_os #=> Integer
resp.commit_transaction.consumed_i_os.write_i_os #=> Integer
resp.abort_transaction.timing_information.processing_time_milliseconds #=> Integer
resp.execute_statement.first_page.values #=> Array
resp.execute_statement.first_page.values[0].ion_binary #=> String
resp.execute_statement.first_page.values[0].ion_text #=> String
resp.execute_statement.first_page.next_page_token #=> String
resp.execute_statement.timing_information.processing_time_milliseconds #=> Integer
resp.execute_statement.consumed_i_os.read_i_os #=> Integer
resp.execute_statement.consumed_i_os.write_i_os #=> Integer #=> Array[0].ion_binary #=> String[0].ion_text #=> String #=> String
resp.fetch_page.timing_information.processing_time_milliseconds #=> Integer
resp.fetch_page.consumed_i_os.read_i_os #=> Integer
resp.fetch_page.consumed_i_os.write_i_os #=> Integer


  • params (Hash) (defaults to: {})


Options Hash (params):

  • :session_token (String)

    Specifies the session token for the current command. A session token is constant throughout the life of the session.

    To obtain a session token, run the StartSession command. This SessionToken is required for every subsequent command that is issued during the current session.

  • :start_session (Types::StartSessionRequest)

    Command to start a new session. A session token is obtained as part of the response.

  • :start_transaction (Types::StartTransactionRequest)

    Command to start a new transaction.

  • :end_session (Types::EndSessionRequest)

    Command to end the current session.

  • :commit_transaction (Types::CommitTransactionRequest)

    Command to commit the specified transaction.

  • :abort_transaction (Types::AbortTransactionRequest)

    Command to abort the current transaction.

  • :execute_statement (Types::ExecuteStatementRequest)

    Command to execute a statement in the specified transaction.

  • :fetch_page (Types::FetchPageRequest)

    Command to fetch a page.


See Also:

# File 'gems/aws-sdk-qldbsession/lib/aws-sdk-qldbsession/client.rb', line 531

def send_command(params = {}, options = {})
  req = build_request(:send_command, params)