Synchronous buffer flushes on MF

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1

Dear Friends,

i want to know, when the synchronous buffer flushes of ADABAS on MF starts and how it functions, which parameters are responsible for it ? :shock:

By asynchronous buffer flushes of ADABAS we have a parameter LFIOP. But it must be 0 by synchronous buffer flushes. :frowning:

have a nice day !

kind Regards,

Sedo

2

When LFIOP=0 the TFLUSH parameter (“time allowed for a synchronous buffer flush”) comes into effect.

But why would you want to use synchronous bufferflush ?

3

thank you Wolfgang ! :smiley:

i want to now, how the " Sync. Buffer flushes on MF " is functioning and when ADABAS makes a sync. buffer flush ( dependence of parameters ) ? :frowning:

kind Regards,

Sedo

4

sorry, i saw your question later !

I´d just like to improve my knowledge, how it is functioning !

5

LFIOP determines if a Bufferflush is synchronous or asynchronous.

Basically the following events cause a buffer flush:

  • ADAEND or HALT
    Autorestart/Autobackout
    Checkpoint command is issued (C1 with COP1/2 = �F�)
    UTI open of a utility
    Start and end of ADASAV SAVE Online
    The oldest block having either an active or write flag must be overwritten
    WORK Part 1 has wrapped around without a buffer flush

Now, the main control instrument over a sync. bufferflush is the TFLUSH parameter.

At nucleus startup, ADABAS estimates how many update blocks can be written out to ASSO/DATA in “TFLUSH” seconds.

After this number of blocks has been updated, the nucleus initiates a buffer flush and keeps track of how long it takes.
The number of blocks to be written out on the next buffer flush is based on this time period.
ADABAS employs a self-correcting algorithm to guarantee a bufferflush takes “TFLUSH” seconds as accurately as possible.

6

thank you Wolfgang ! :lol:

greetinx

:smiley: