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Hi Thomas, I don't have a real answer for that. Obviously, some data had to be read into the cache. I seems to be the way "read into cache" is calculate and is sensitive to the actual read size. So, I guess you could classify it as a bug. The other statistics seem OK. Andy On Wed, 4 Mar 2020, Thomas Byrne - UKRI STFC wrote: > Hi, > > Thanks for this Andy, it's very helpful. > > I'm confused why 'Read' is *always* zero on our cache log stats, I would have expected it to be a multiple of the pagesize. Have I got the wrong end of the stick here? > > Cheers > Tom > >> -----Original Message----- >> From: [log in to unmask] <[log in to unmask]> On >> Behalf Of Andrew Hanushevsky >> Sent: 02 March 2020 23:59 >> To: Patargias, George (STFC,RAL,SC) <[log in to unmask]> >> Cc: [log in to unmask] >> Subject: Re: Meaning of memory cacheing log stats >> >> Hi George, >> >> So, here it is: >> >> 0 Read; Total number of bytes read into the cache >> 38581 Get; Number of bytes delivered from the cache >> 0 Pass; Number of bytes read but not cached >> 0 Write; Total number of bytes written from the cache >> 0 Put; Number of bytes updated in the cache >> 20 Hits; Number of times wanted data was in the cache >> 3 Miss; Number of times wanted data was *not* in the cache >> 0 pead; Bytes read via preread (not included in BytesRead) >> 0 HitsPR; Number of pages of wanted data was just preread >> 0 MissPR Number of pages of unwanted data was just preread >> >> So, it would seem the cache is being effective as number of hits is far greater >> than the number of misses. >> >> Andy >> >> >> On Mon, 2 Mar 2020, George Patargias - UKRI STFC wrote: >> >>> Hello, >>> >>> >>> We have turned on the printing of mem cache statistics using the >>> "logstasts" flag of the pss.cache >>> >>> directive as shown below >>> >>> >>> pss.cache logstats max2cache 33554432 pagesize 33554432 size >>> 17179869184 >>> >>> >>> Can you please explain briefly what is the meaning of the numbers >> appearing in the corresponding lines of the xrootd log? The following is a >> common example we see on our xrootd server but it is not clear whether the >> cache is being effective in this case (we suspect it isn't). >>> >>> >>> Cache: Stats: 0 Read; 38581 Get; 0 Pass; 0 Write; 0 Put; 20 Hits; 3 >> Miss; 0 pead; 0 HitsPR; 0 MissPR; Path >>> >>> >>> Thanks, >>> >>> >>> George >>> >>> >> ############################################################ >> ########## >>> ## >>> Use REPLY-ALL to reply to list >>> >>> To unsubscribe from the XROOTD-L list, click the following link: >>> https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=XROOTD-L&A=1 >>> >> >> ############################################################ >> ############ >> Use REPLY-ALL to reply to list >> >> To unsubscribe from the XROOTD-L list, click the following link: >> https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=XROOTD-L&A=1 > ######################################################################## Use REPLY-ALL to reply to list To unsubscribe from the XROOTD-L list, click the following link: https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=XROOTD-L&A=1