Hi there,

I am new with vibe.d and D-lang. I've written a program to execute x set
commands in Redis but the performance is really bad for 1M or more
commands.
Maybe I am doing something silly and at the moment I am not aware of another
way to do it better. It seems it is not running asynchronous, I have tried
using the configuration for libevent and libasync but the performance was pretty much the same. Maybe there is something
wrong in the way I set the task?
Any suggestion will be appreciated. Thanks in advance.

The program 

module app;

import vibe.core.core;
import vibe.core.log;
import vibe.db.redis.redis;
import std.exception : assertThrown;
import std.conv;
import std.format;
import std.getopt;

void runTest (ulong num_records)
{
    logInfo("Test starting");

	RedisClient redis;
	try redis = new RedisClient();
	catch (Exception) {
		logInfo("Failed to connect to local Redis server.");
		return;
	}

    auto task = {  
        foreach (i; 0..num_records)
        {
            redis.getDatabase(0).set("Key%d".format(i), "Value%d".format(i));
        }
    };
    
    auto t1 = runTask(task);
    t1.join();

	logInfo("Test finished.");
}

int main (string[] args)
{
    auto num_records = 1_000_000UL;

    getopt(args, "records|n", &num_records);

	int ret = 0;
	runTask({
		try runTest(num_records);
		catch (Throwable th)
        {
			logError("Test failed: %s", th.msg);
			logDiagnostic("Full error: %s", th);
			ret = 1;
		}
        finally exitEventLoop(true);
	});
	runEventLoop();

	return ret;
}

This is how I run it: 

$ /usr/bin/time -v -p sh -c 'dub run bulktest -b release'
Building package bulktest in /home/daniz/projects/vibe.d/tests/myredis/
Performing "release" build using dmd for x86_64.
diet-ng 1.2.1: target for configuration "library" is up to date.
vibe-d:utils 0.8.0-rc.3+commit.2.ge84c45dd: target for configuration "library" is up to date.
vibe-d:data 0.8.0-rc.3+commit.2.ge84c45dd: target for configuration "library" is up to date.
vibe-d:core 0.8.0-rc.3+commit.2.ge84c45dd: target for configuration "libevent" is up to date.
vibe-d:crypto 0.8.0-rc.3+commit.2.ge84c45dd: target for configuration "library" is up to date.
vibe-d:stream 0.8.0-rc.3+commit.2.ge84c45dd: target for configuration "generic" is up to date.
vibe-d:textfilter 0.8.0-rc.3+commit.2.ge84c45dd: target for configuration "library" is up to date.
vibe-d:diet 0.8.0-rc.3+commit.2.ge84c45dd: target for configuration "library" is up to date.
vibe-d:inet 0.8.0-rc.3+commit.2.ge84c45dd: target for configuration "library" is up to date.
vibe-d:http 0.8.0-rc.3+commit.2.ge84c45dd: target for configuration "library" is up to date.
vibe-d:redis 0.8.0-rc.3+commit.2.ge84c45dd: target for configuration "library" is up to date.
bulktest ~master: target for configuration "application" is up to date.
To force a rebuild of up-to-date targets, run again with --force.
Running ./bulktest 
Test starting
Test finished.
	Command being timed: "sh -c dub run bulktest -b release"
	User time (seconds): 15.77
	System time (seconds): 14.18
	Percent of CPU this job got: 73%
	Elapsed (wall clock) time (h:mm:ss or m:ss): 0:40.99
	Average shared text size (kbytes): 0
	Average unshared data size (kbytes): 0
	Average stack size (kbytes): 0
	Average total size (kbytes): 0
	Maximum resident set size (kbytes): 14564
	Average resident set size (kbytes): 0
	Major (requiring I/O) page faults: 0
	Minor (reclaiming a frame) page faults: 3410
	Voluntary context switches: 999775
	Involuntary context switches: 1247
	Swaps: 0
	File system inputs: 0
	File system outputs: 8
	Socket messages sent: 0
	Socket messages received: 0
	Signals delivered: 0
	Page size (bytes): 4096
	Exit status: 0

Version of the compiler: DMD64 D Compiler v2.071.2
OS: Ubuntu Linux 16.04