Q: How can I monitor the performance of my Web site graphically?

A: With a souped-up version of percollator.se and an accompanying set of graphing tools called Orca. We'll discuss both in this month's column.

Back when I first built percollator.se, I had grand visions of what
this tool could do. But many things got in the way, and percollator never
quite realized its potential -- until Blair Zajac of GeoCities went to
town, that is. Blair customized percollator to monitor the GeoCities Web site,
and he built a very nice graph generator to summarize the data he
collected. Because this is exactly the kind of thing I wanted to happen
when I built the tool in the first place, I decided to touch on it here.

First, Blair identified a bug in percollator.se that overestimates the
Web server hit rate for the peak five-second period by assuming that
each measurement really is taken five seconds apart. In actuality, the
process of measuring and writing an output record can take much longer
than five seconds. Blair fixed the problem by using an accurate
measurement of the actual time delay for this calculation. This fixed
version is included in the latest build of SE 3.1, which is available on
the download site (see Resources).

Blair also built a set of graphing tools called Orca and a greatly
extended version of percollator.se, which we've included in SE 3.1 as
orcollator.se. The percollator.se and orcollator.se tools
generate a space-delimited table of data,
with each day in a separate file. Each file has one row of many columns
and includes all the data measured within each five-minute period. The
Orca tools build a set of Web pages that let you view multiple systems
over various timescales and pick out any of the measured data. You can
use Orca to generate detailed plots as GIF images. An example is shown
below.

For a live example, more information, and to download Orca visit Blair's
Web site (see Resources).

Updated SE 3.1 release

We found relatively few problems with the SE 3.1 beta release, which
has already been installed numerous times on every kind of system from
Intel PCs and SPARCstation 1s to E10000s. I detailed a number of
changes appearing in the beta release in my February
column.

Rich Pettit has built yet another new version, currently called
prefcs, which includes the following changes:

• The install script now checks for Solaris 2.5.1 and exits (we saw
  some attempts to install on 2.5.1); the earliest release supported is
  Solaris 2.6.

• Mike Bennett fixed and updated 64-bit ndd interface and tcp_monitor.se.

• We built in a number of math functions, so you don't have to build
  wrappers and pass pointers to doubles. (The 32-bit build of SE cannot
  pass 8-byte values to attached functions.)

• We now use dynamically resized arrays for the disk, network, and CPU
  classes. If more devices appear, or if SE is confused about how
  many devices exist to start with, the arrays will grow to size.

• We fixed some printf format bugs in virtual_adrian.se and included
  a Discworld reference to the error
  message printed if the program exits due to lack of swap space. The
  static check and tune code automatically turns on priority_paging if it's
  available and if the script has root permissions. For a description of
  priority_paging, see http://www.sun.com/sun-on-net/performance/priority_paging.html.

• The test that determines which devices to place in the
  disk rule now tests disks that don't have mounted partitions.

• We updated percollator.se to include Squid proxy cache log parsing,
  as well as a more accurate five-second peak measure and more
  flexible log-file parsing.

• We added orcollator.se to give more comprehensive Web server
  metrics.

We still need to work out one more egregious kink: some "unplumbed" hme network interfaces can cause SE to go into an
infinite loop.

We still have a long wish list of fixes, but either we don't have time,
or some other problem is preventing a fix. Here are a few of the items on our list:

• SE (and iostat and sar) can't see VxVM volumes because they don't
  generate the same I/O kstat measurements as do regular disks and Disksuite
  volumes. We've raised this issue with Veritas, but it doesn't
  seem interested in fixing it.

  
  It is possible to use the RM6 commands to obtain the volume configuration of an
  A1000 or A3000/3500, and metastat and vxprint to obtain the
  configuration of Disksuite and VxVM for more detailed disk volume
  display and monitoring rules.

• SE doesn't distinguish between different types of network
  interfaces and disk subsystems. The current rules are too generic.

• The NFS rule needs to be updated to take into account the NFS io
  kstats and NFSv3 over TCP metrics.

For bug reports, please send e-mail to Rich Pettit and me ( href="mailto:se-feedback@chessie.eng.sun.com">se-feedback@chessie.eng.sun.com).
If you're interested in writing new code in SE, sign up for the SE
developers' alias, so you can access interim test builds of the
toolkit. The current SE toolkit release is available for download (see
Resources).

Proctool now supports Solaris 7

Morgan Herrigton updated Proctool for both SPARC and Intel platforms.
Pick up your copy from ftp://nce.sun.ca/pub/freeware/SOURCES/PROCTOOL/proctool_1999_04.tar.gz.

Unlike previous releases, this single distribution contains binaries to support Solaris 2.4 through Solaris 7 (32- and 64-bit) on SPARC, and Solaris 2.5 through Solaris 7 on x86. Changes in this release include

• Fixed Y2K bug ("start date" field changed to YYYY/MM/DD)
• Support for Solaris 7 (both 32- and 64-bit on SPARC)
• ASCIIinit file (for compatibility between 32- and 64-bit versions)
• Font selections for non-Solaris displays
• Increased capacity limits

Contact morgan.herrington@west.sun.com for questions about Proctool, or if you would like to be added to the Proctool interest alias.

That's all for this month.

• Dr. Blair Zajac's home page
  
  http://www.gps.caltech.edu/~blair/

• Online performance information home page
  
  http://www.sun.com/sun-on-net/performance.html

• SE download site
  
  http://www.sun.com/sun-on-net/performance/se3

• virtual_adrian.se rule
  
  http://www.sun.com/951001/columns/adrian/column2.html

• Detailed two-part whitepaper that describes how to optimize for performance on Sun systems
  
  http://www.sun.com/software/white-papers/wp-optimize/optimize-part1.pdf
  
  http://www.sun.com/software/white-papers/wp-optimize/optimize-part2.pdf

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