LP Spooler is slow

[GUENIER]

Whith HPUX 10.20, when we send a file on network HP Laser printer with lp command, data arrive after 7 secondes on the printer.

The same printer is very fast with a cups print server (with samba).

I think there is a probleme with LP scheduler.

When I restart the scheduler (with the "lpsched" command), there is 2 lpsched process:

/#ps -fe | grep lpsched root 27031 19977 1 14:56:19 ttyr6 0:00 grep lpsched
lp 26522 26521 0 14:49:21 ? 0:00 lpsched
lp 26521 1 0 14:49:21 ? 0:00 lpsched
/#

Is it normal ???

Can anyone help us ??

[A. Clay Stephenson]

Well, if data start arriving at the printer after 7 seconds that doesn't seem very slow to me. Without knowing more, it's difficult to say if this is bad or good. You may have a very elaborate filter program in place. It would also help to know if this is a Remote or Network printer.

In any event, it is perfectly normal to see multiple lpsched processes because everytime lp is invoked, lpsched fork()'s a new process. In your ps listing note that one lpsched has PPID = 1 (init); it is the actual daemon; the other lpsched is a child process of this one. These child lpsched processes are normally short lived.

[Bill Hassell]

Let's start by measuring when the data actually arrives. Unless this is an ancient dot matrix or giant green-bar paper line printer, modern printers do not pop out paper or even start the rollers moving as soon as data arrives. Instead, the printer stores the incoming data until a complete page is received. If this is not a plain ASCII page but consists of special fonts and graphics, the amount of data can be significant (megabytes) just for the first page. And of course, really old technology printers may take several seconds (minutes?) to process and format the image before the paper actually moves.

Now many printers have an activity light, something that flashes when data starts arriving. If you have this indicator, use it to determine whether the data is delayed. There is nothing in the lp spooler that can delay or slow down data transfers. If the printer is connected with a serial or parallel cable (which is extremely slow), I would immediately replace the connection with a network adapter such as the HP JetDirect card.

You can bypass the lp spooler by sending data direct to the printer but the details very much depend on which of the 3 different connection methods you are using (direct connect as in serial or parallel, remote printing to some server or non-HP LAN adapter, oe HP JetDirect LAN adapter).

You may find that the delay is in the printer, not in the spooler, and completely normal. Most laser printers require not only a formatting period but many require a warmup if they have been idle for several minutes.