It's not that classic FTP is slow; it's the FTP API that is unexplainably slow.
I have some hard numbers now. The IBM-supplied API sample program takes six elapsed seconds on the Dallas z14. The classic FTP client performing EXACTLY the same transfers from INPUT DD * with the same site (our Dallas machine via its IP address) took two seconds. The sample program does a bit of processing of the data -- searching for the largest file in the listing returned from DIR /tmp/* -- but that should not account for four seconds. Would love to have an IBMer comment. Charles -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of kekronbekron Sent: Tuesday, October 26, 2021 9:14 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: Performance issues with the FTP API There was a post within the past year about FTP being slow. It came down to reverse DNS lookups I think. Just something to look up perhaps. - KB ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐ On Wednesday, October 27th, 2021 at 12:03 AM, Charles Mills <charl...@mcn.org> wrote: > Questions for anyone who has used the z/OS FTP API: > > Are you seeing poor performance? For example, we are seeing FAPI_INIT taking > > about four seconds (whereas the real FTP client starts up almost > > immediately). We are seeing a sequence of four RMDIR's taking about four > > seconds (on a local connection where the real FTP client does it effectively > > instantaneously). > > A particular set of functionality -- start to finish -- takes about seven > > seconds with the real FTP client. A comparable functionality -- not exactly > > the same, but roughly the same -- takes 31 seconds with the FTP API. > > Is this what others are seeing? Has anyone discovered any particular > > gotcha's? The programmer was loading the stub dynamically rather than > > statically, but fixing that only knocked it down from 40 seconds to 31. > > This is on a z14 under V2R4. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
