Query on the Load Balancing ?

Question

Guys
I would like to understand how the FAV_COMPUTE_TIME has been calculated for the system to indentify the FAV_COMPUTE_SERVER
I have enclosed a snapshot of our prd server.Appreciate  advise on this subject
Integer-Storage             MSGSERVER
REL_SYSTEM               4,640      8,464          0          0          0          0          0          0          0          0
REL_PATCHNO_00000144     2,381      8,465          0          0          0          0          0          0          0          0
sapdp16_P16_16          58,643      7,353        122          5         46        520         14          0          0         21
sapap16b_P16_16         58,867      7,353        539        179        214        201         16          0  *73741824-        56
sapap16a_P16_16         58,736      7,353        889        215        184         20         16          0  *73741824-        63
sapap16c_P16_16         58,804      7,353        650        192        181        156         16          0  *73741824-        49
sapap16d_P16_16         58,758      7,353        664        145        173        150         16          0  *73741824-        94
Short-Text-Storage          MSGSERVER
FAV_COMPUTE_TIME     FAV_COMPUTE_TIME    58867
FAV_COMPUTE_SERVER   sapap16b_P16_16     16:21:07
Logon Favorite Storage          MSGSERVER
P16                  3,216  46C  (sapap16b_P16_16)
P16-TPA              3,216  46C  (sapap16b_P16_16)
SPACE                3,216  46C  (sapdp16_P16_16)
USED-BY-BW           3,216  46C  (sapap16b_P16_16)
USED-BY-EBPRO        3,216  46C  (sapap16b_P16_16)
Long-Text-Storage           MSGSERVER
Regards
Karthi

Answer 1

Hello Karthi,
I would like to understand how the FAV_COMPUTE_TIME has been calculated for the system to indentify the FAV_COMPUTE_SERVER
Short-Text-Storage          MSGSERVER
FAV_COMPUTE_TIME     FAV_COMPUTE_TIME    58867
FAV_COMPUTE_SERVER   sapap16b_P16_16     16:21:07
the value for FAV_COMPUTE_TIME is very easy to calculate: simply count the seconds since midnight, i.e. the value 58867 only represents the time stamp 16:21:07 (16 hours = 57600 seconds, 21 minutes = 1260 seconds. 5760012607=58867).
Very easy, isn't it?
In other words: the information FAV_COMPUTE_TIME and FAV_COMPUTE_SERVER is only a remark at what time an instance has forwarded its load information to the message server. It has nothing to do with the quality value itself. In your example the instance sapap16b_P16_16 has calculated and forwarded its load information (resp.time 539ms, 214 users, quality value 201) at 16:21:07. But this does not mean that this instance is automatically the favourite instance (ok, in your example it is indeed the favourite instance for all logon groups, but that's only by chance. Some minutes later most probably sapap16b_P16_16 is still favourite server for the logon groups but for FAV_COMPUTE_SERVER another instance is listed).
Personally I think it is sufficient to have a look at the load distribution screen in SMLG (Goto - Load distribution (or simply F5)) than to try to guess araound what exactly the figures in the message server status area mean.
But if I understand you correctly you are more interested how this mysterious quality value is calculated, right?
It is calculated in report RSRZLLG0 (or more detailed in RSRZLLG0_ACTUAL) which is started on each instance each five minutes (by sapmssy6) and each fifth logon.
Believe a simple maths is involved
Not, not really simple. The report uses as well response time and the number of logged on users. But it uses also the difference between the current values and the thresholds (if they are used), i.e. if the number of users is very close to the (defined) threshold the quality will be lower than compared to an instance with less users (and same threshold).
Also the report calculates at first each part seperately (users, response time) and uses then an additional weighting so that the response time has more influence than the number of users (see also the already mentioned [note 51789|http://service.sap.com/sap/support/notes/51789]).
Maybe describing the principle as it happened know contains enough information for you, but if you really want to understand the coding in every detail, you should ask an ABAPer to explain it to you
Regards, Michael