Fix AOFRW limit test occasional failures on slower machines

[chenyang8094]

issue link: #9788 (comment)

[oranagra]

this isn't very efficient (many small keys which unknown size, and also no pipeline).
why not just a single SETRANGE x 1024 1?
or if we want many small keys populate 1024

[chenyang8094]

I think you misunderstood the mechanism of AOFRW's auto-triggering, IIUC redis compares the number of bytes written to the AOF file, not the number of keys in redis.

if (server.aof_state == AOF_ON &&
            !hasActiveChildProcess() &&
            server.aof_rewrite_perc &&
            server.aof_current_size > server.aof_rewrite_min_size &&
            !aofRewriteLimited())
{
     AOFRW();
}

[oranagra]

ohh, right (not misunderstood, just forgot for a moment).
so scrap the SETRANGE suggestion.
it can be r SET x [string repeat x 1024], or populate 1024 (to get multiple keys)

[chenyang8094]

populate 1024 doesn't work，because it won't be written to AOF.
r SET x [string repeat x 1024] is a good suggestion.

p.s. I found that when changing auto-aof-rewrite-min-size to 1kb, AOFRW will be triggered automatically (because a lot of data was written in the previous test, causing server.aof_current_size to exceed 1KB). So at the beginning of the test, I first flush the data and executed an AOFRW to ensure that server.aof_current_size is 0.

[oranagra]

ok.. but not sure why populate won't work. it's a function (not DEBUG POPULATE).

# Write num keys with the given key prefix and value size (in bytes). If idx is
# given, it's the index (AKA level) used with the srv procedure and it specifies
# to which Redis instance to write the keys.
proc populate {num {prefix key:} {size 3} {idx 0}} {
    set rd [redis_deferring_client $idx]
    for {set j 0} {$j < $num} {incr j} {
        $rd set $prefix$j [string repeat A $size]
    }
    for {set j 0} {$j < $num} {incr j} {
        $rd read
    }
    $rd close
}

[chenyang8094]

ohh, I did understand it was debug populate, you are right.