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Ex Libris Knowledge Center

Slow system response during check-out (loan)

  • Article Type: General
  • Product: Aleph
  • Product Version: 20

Description:
There are two problems:

1. It takes at least two seconds to check out an item

2. When a patron has 200 items checked out, it takes 3.4 seconds per item. When a patron has 300 items it would take 5+ seconds per item. Etc.

[See Additional Information below for full description.]

Resolution:
Our experience has been that two seconds is a typical response time for a loan transaction. It may also be that 3.4 seconds is a typical time for a patron with 200 items (and 5+ seconds, with 300 items). Sites have not reported this issue previously, so we do not have previous experience.

The element which usually takes the longest is I/O ... with sort time as a factor in some cases.

The loan progam (pc_cir_c0441) reads all of the following: z30, z303, z36, z305, z31, z37.
And it writes z36, z30, z35, z309.

Article 000044836 ("Slow check-out of items which have been loaned many times") discusses slow check-out of items which have been loaned many times (and includes a solution).

In the case where the patron has many Cash records, that could, as described at the end of this answer, be a factor. Otherwise, I do not see much that could be done to improve the basic check-out time of 2 seconds.

The phenomenon of increased check-out time for patrons with a large number of items checked out has to do with programs reading all of the items the patron has on loan. Certain tab_check_circ programs do this. They are listed below:

! 4_a: check patron loan limits
! check the patron's loan limits according to parameters
! set in tab16 (col.12)
! 4_b: check patron loan limits (99 line)
! check the patron's overall loan limit in a sublibrary
! according to parameters set in tab16 99 line
! 4_c: check patron loan limits (99 line)
! check the patron's overall total loan limits for ADM library
! according to parameters set in tab16 99 line

! 9_a: check overdues and fines -ADM library
! checks maximum overdues, recalled overdues and fines, for the
! ADM library based on tab_block_circ
! 9_b: check overdues and fines -sublibrary
! checks maximum overdues and recalled overdues in a sublibrary
! based on tab_block_circ
! 10_a: same as 9_a except that all loans are taken into account -
! active, lost and claimed return
! 10_b: same as 9_b except that all loans are taken into account -
! active, lost and claimed return

A test could be conducted with the above checks commented out. If it improves the time, then having only one of the _4_x checks enabled could be considered.

Though it is not related to the phenomenon of the increasing check-out time for patrons with increasingly large numbers of items on loan, in cases where the patron has many z31 cash records, reading of these records (to produce the "Owe" amount in the Cash display on the upper right of the Loan screen, and to perform the tab_check_circ check_circ_5 and _5a checks), can take a significant part of the response time. If the patron is one who has many cash records, try it with a patron who has fewer (or none) to see if that makes a difference. If it seems that it does, consider deleting older, closed Cash records.

Additional Information

Slow check-out of items which have been loaned many times

**Full Description**
There are two problems:

 1. It takes at least two seconds to check out an item

 2. When a patron has 200 items checked out, it takes 3.4 seconds per item.  When a patron has 300 items it would take 5+ seconds per item. Etc.

In our first test, which was conducted in late January of 2009, we timed how long it took to check out 15 items to three different patrons.  The first patron had 0 books already on loan, the second patron had 10 books already on loan, and the third patron had 75 books already on loan.  This was conducted four times a day, for four days.

The average amount of time it took to check out 15 items to a patron with 0 books already on loan:  31.3 seconds
The average amount of time it took to check out 15 items to a patron with 10 books already on loan:  33 seconds
The average amount of time it took to check out 15 items to a patron with 75 books already on loan:  37.8 secs 
In the second test, which was conducted in early July of 2009, we timed how long it took to check out 25 books to a patron with 15 items already on loan, 40 books already on loan, 65 books already on loan, and 90 books already on loan.  This was conducted three times, on three different days.

The average amount of time it took to check out 25 items to a patron with 15 books already on loan:  54.6 secs
The average amount of time it took to check out 25 items to a patron with 40 books already on loan:  55.7 secs 
The average amount of time it took to check out 25 items to a patron with 65 books already on loan: 57.9 secs
The average amount of time it took to check out 25 items to a patron with 90 books already on loan: 60.8 secs

Although not specifically documented with our test above, we experience a similar delay when checking items in.

Category: Circulation


  • Article last edited: 7/1/2015