Bus Error/wsfull error

Community Support
1

Hi,

We are working on a test application which is currently writing dummy
data in a loop to a ticker plant/RTD setup. The q table the
application is writing to has 32 columns. We tried it on 2 boxes (both
64 bit boxes using 64 bit c.o versions) and on one we get “bus error”
on the RTD (after which it crashes) and on another box we get “wsfull”
error after about 8.5 million inserts. In both these scenarios, ticker
plant and the application keep on running with the tp log file size
increasing. Even, if RTD is attempted to be re-started it tries
reading from the log file for a few minutes but crashes with bus error
and wsfull respectively.

Are we hitting some kind of limit here with q? or are we doing
something wrong?
Please find some of the code below.

Regards,
Vishal.

Code snippet:

void func()
{
K col[32];

for(j=0;j<32;j++)
col[j] = ktn(KS,0);
string temp =“abcdefgh”;
for(j=0;j<32;j++)
{
js(&(col[j]), ss((S)temp.c_str()));
}
K data, x;
data = knk(32, col[0], col[1], col[2], col[3], col[4], col[5], …
col[31]);
x=k(-c,“.u.upd”, ks ((S)“fixTags”),data,K(0));
}

int main()
{
c=khp(“171.130.67.85”,7010);
Q(c<0,“connect”);
count = 0;
for ( int i ==0 ; i < 15000000; i ++) // trying to insert 15M
func();
return 0;
}

2

X-Mailer: Apple Mail (2.936)

wsfull is memory space exhausted. try a 64bit kdb.
you get bus error when you are accessing unaligned memory from your c
code. what kind of machine is running your kdb servers?

felix

3

if you’re using 64bit versions of kdb+ then you must be a licensed customer, in which case you should report (suspected) bugs directly to Kx.

32 columns of sym type, each 4 byte pointers on 32bit, 8.5 million inserts, puts you at over 1GB of raw data.

Depending on mem fragmentation, you’re probably hitting the 32bit limits (I assume you are using the 32bit non-commercial download version).

(It’s helpful for troubleshooting if users include the banner printed by kdb+ on startup.)

4

We are using the 64 bit version (licensed customer) q exe and also 64bit version of c.o … Thanks … we will report this directly to kx.Sorry about posting it here.As for kdb+ details during start up please find them below:l64/ 1()core 7915MBRegards,vcdOn Aug 28, 7:42?pm, Charles Skelton <char…> wrote:> if you’re using 64bit versions of kdb+ then you must be a licensed customer,> in which case you should report (suspected) bugs directly to Kx.>> 32 columns of sym type, each 4 byte pointers on 32bit, 8.5 million inserts,> puts you at over 1GB of raw data.>> Depending on mem fragmentation, you’re probably hitting the 32bit limits (I> assume you are using the 32bit non-commercial download version).>> (It’s helpful for troubleshooting if users include the banner printed by> kdb+ on startup.)>>>> On Fri, Aug 28, 2009 at 2:53 PM, vcd <vcdo…> wrote:>> > Hi,>> > We are working on a test application which is currently writing dummy> > data in a loop to a ticker plant/RTD setup. The q table the> > application is writing to has 32 columns. We tried it on 2 boxes (both> > 64 bit boxes using 64 bit c.o versions) and on one we get “bus error”> > on the RTD (after which it crashes) and on another box we get “wsfull”> > error after about 8.5 million inserts. In both these scenarios, ticker> > plant and the application keep on running with the tp log file size> > increasing. Even, if RTD is attempted to be re-started it tries> > reading from the log file for a few minutes but crashes with bus error> > and wsfull respectively.>> > Are we hitting some kind of limit here with q? or are we doing> > something wrong?> > Please find some of the code below.>> > Regards,> > Vishal.>> > Code snippet:>> > void func()> > {> > ? ?K col[32];>> > ? ?for(j=0;j<32;j++)> > ? ? ? ? ? ?col[j] = ktn(KS,0);> > ? ?string temp =“abcdefgh”;> > ? ?for(j=0;j<32;j++)> > ? ?{> > ? ? ? ? ? ?js(&(col[j]), ss((S)temp.c_str()));> > ? ?}> > ? ?K data, x;> > ? ?data = knk(32, col[0], col[1], col[2], col[3], col[4], col[5], …> > col[31]);> > ? ? x=k(-c,“.u.upd”, ks ((S)“fixTags”),data,K(0));> > }>> > int main()> > {> > ? ? ? ?c=khp(“171.130.67.85”,7010);> > ? ? ? ?Q(c<0,“connect”);> > ? ? ? ?count = 0;> > ? ? ? ?for ( int i ==0 ; i < 15000000; i ++) // trying to insert 15M> > ? ? ? ? ? ?func();> > ? ? ? ?return 0;> > }- Hide quoted text ->> - Show quoted text -</vcdo…></char…>

5

X-Mailer: Apple Mail (2.936)> As for kdb+ details during start up please find them below:> l64/ 1()core 7915MBthe first line is also important (version and date). i usually post like this, only censoring username, hostname, IP, and license info:% qKDB+ 2.4 2008.03.31 Copyright (C) 1993-2008 Kx Systemsm32/ 2()core 2048MBq)