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Spread checks over time with with max slop time #848

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Spread checks over time with with max slop time #848

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31 changes: 29 additions & 2 deletions ldirectord/ldirectord.in
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Original file line number Diff line number Diff line change
@@ -153,6 +153,23 @@ but ONLY if using forking mode (B<fork = >I<yes>).

Default: 10 seconds

B<checkintervalspread = >I<n>

Defines the maximum number of second to be randomly added to checkinterval.

When fork=no this option is not used.
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There is no code for this that I can see?

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Sorry, ignore that - it's in run_child() rather than ld_main() so it's fine.


When fork=yes this option defines the maximum additional amount of time
each forked child sleeps per virtual service pool before running all
realserver checks for that pool.

If set in the virtual server section then the global value is overridden.

This option causes checks to spread out in time, in order to avoid
overloading services probed using the same test.
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Abstracting checks from services might be nicer, but that would be much more difficult to do.


Default: 0 seconds

B<checkcount = >I<n>

This option is deprecated and slated for removal in a future version.
@@ -770,6 +787,7 @@ use vars qw(
$VERSION_STR
$AUTOCHECK
$CHECKINTERVAL
$CHECKINTERVALSPREAD
$LDIRECTORD
$LDIRLOG
$NEGOTIATETIMEOUT
@@ -858,7 +876,7 @@ set_defaults();
use Getopt::Long;
use Pod::Usage;
#use English;
#use Time::HiRes qw( gettimeofday tv_interval );
use Time::HiRes qw(sleep);
use Socket;
use Socket6 qw(NI_NUMERICHOST NI_NUMERICSERV NI_NAMEREQD getaddrinfo getnameinfo inet_pton inet_ntop);
# Workaround warnning messages : Three "_in6" symbols redefined.
@@ -1275,6 +1293,7 @@ sub set_defaults
$CALLBACK = undef;
$CHECKCOUNT = 1;
$CHECKINTERVAL = 10;
$CHECKINTERVALSPREAD = 0;
$CHECKTIMEOUT = -1;
$CLEANSTOP = "yes";
$DEFAULT_CHECKTIMEOUT = 5;
@@ -1455,6 +1474,9 @@ sub read_config
} elsif ($rcmd =~ /^checkinterval\s*=\s*(.*)/){
$1 =~ /(\d+)/ && $1 or &config_error($line, "invalid checkinterval");
$vsrv{checkinterval} = $1
} elsif ($rcmd =~ /^checkintervalspread\s*=\s*(.*)/){
$1 =~ /(\d+)/ && $1 or &config_error($line, "invalid checkintervalspread");
$vsrv{checkintervalspread} = $1
} elsif ($rcmd =~ /^checkport\s*=\s*(.*)/){
$1 =~ /(\d+)/ or &config_error($line, "invalid port");
( $1 > 0 && $1 < 65536 ) or &config_error($line, "checkport must be in range 1..65536");
@@ -1682,6 +1704,10 @@ sub read_config
$1 =~ /(\d+)/ && $1 or &config_error($line,
"invalid check interval value");
$CHECKINTERVAL = $1;
} elsif ($linedata =~ /^checkintervalspread\s*=\s*(.*)/) {
$1 =~ /(\d+)/ && $1 or &config_error($line,
"invalid check interval spread value");
$CHECKINTERVALSPREAD = $1;
} elsif ($linedata =~ /^checkcount\s*=\s*(.*)/) {
$1 =~ /(\d+)/ && $1 or &config_error($line,
"invalid check count value");
@@ -2721,6 +2747,7 @@ sub run_child
my $real = $$v{real};
my $virtual_id = get_virtual_id_str($v);
my $checkinterval = $$v{checkinterval} || $CHECKINTERVAL;
my $checkintervalspread = $$v{checkintervalspread} || $CHECKINTERVALSPREAD;

# delete any entries in EMAILSTATUS that don't belong to this child
my %myservices = ();
@@ -2740,7 +2767,7 @@ sub run_child
_check_real($v, $r);
}
$0 = "ldirectord $virtual_id";
sleep $checkinterval;
sleep $checkinterval + (random($$) * $checkintervalspread);
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As noted, should be rand(), and as $$ is the current PID you're multiplying checkintervalspread by what is often likely to be a very large integer, so this becomes something like sleep(a few hours). Which doesn't seem right?

Surely should just be

sleep $checkinterval + rand($checkintervalspread);

?

ld_emailalert_resend();
}
}