[cli] Enable CLI to publish non-batched messages

[massakam]

Motivation

Currently, messages produced by the pulsar-client command are always batched. However, zero queue consumers cannot receive these batched messages. I think it would be useful to be able to easily produce non-batched messages.

Modifications

Added an option to disable batching to the pulsar-client command:

$ ./bin/pulsar-client produce -m hello -n 10 --disable-batching persistent://public/default/t1

Verifying this change

• Make sure that the change passes the CI checks.

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): (no)
• The public API: (no)
• The schema: (no)
• The default values of configurations: (no)
• The wire protocol: (no)
• The rest endpoints: (no)
• The admin cli options: (no)
• Anything that affects deployment: (no)

Documentation

• doc

[codelipenghui]

It better to named --batch-enabled? and the default is true.

[massakam]

Normally, boolean type options do not require a value, so the default value should be false.

# By default batching is enabled
$ ./bin/pulsar-client produce -m hello persistent://public/default/t1

# Batching is enabled in this case as well
$ ./bin/pulsar-client produce -m hello --batch-enabled persistent://public/default/t1

We can set the default value to true by specifying arity = 1, but it may be a bit verbose.
https://jcommander.org/#_boolean

# Batching is enabled
$ ./bin/pulsar-client produce -m hello --batch-enabled true persistent://public/default/t1

# Batching is disabled
$ ./bin/pulsar-client produce -m hello --batch-enabled false persistent://public/default/t1

[codelipenghui]

Ok, that makes sense.

How about keeping the same configurations with the perf producer?

        @Parameter(names = { "-b",
                "--batch-time-window" }, description = "Batch messages in 'x' ms window (Default: 1ms)")
        public double batchTimeMillis = 1.0;

        @Parameter(names = {
            "-bm", "--batch-max-messages"
        }, description = "Maximum number of messages per batch")
        public int batchMaxMessages = DEFAULT_BATCHING_MAX_MESSAGES;

        @Parameter(names = {
            "-bb", "--batch-max-bytes"
        }, description = "Maximum number of bytes per batch")
        public int batchMaxBytes = 4 * 1024 * 1024

if (arguments.batchTimeMillis <= 0.0 && arguments.batchMaxMessages <= 0) {
                producerBuilder.enableBatching(false);
            }

[massakam]

In the pulsar-client command, one batch message always contains only one message, even if batching is enabled. This is because we are using the synchronous method send() instead of the asynchronous method sendAsync().

pulsar/pulsar-client-tools/src/main/java/org/apache/pulsar/client/cli/CmdProduce.java

Line 297 in 3c770a1

message.send();

So, unlike the perf producer, I don't think such fine-grained settings are useful.

[massakam]

There is no particular benefit to enabling batching for the pulsar-client command, so we have the option of always disabling it.

[codelipenghui]

Ok, that make sense.

[Jason918]

It seems that you have not checked if the message is from a batch message.

[massakam]

Is this check not enough? Is there any other good way?

[Jason918]

Oh, sorry, my mistake. It's good.

[Jason918]

Oh, sorry, my mistake. It's good.