A new "throttle" column has been added to HTML and RAW stats to indicate
in percent, the level of throttling due to server warmup. The column is
empty at 100%.
It's important to be able to distinguish between servers which are UP
and those which are UP but disabled via a 404 response. For this reason,
the status entries report "NOLB" instead of "UP", and the HTML page uses
darker colors. As a complement, write "DOWN" in bold red on the backend
if it has no server left for load balancing.
Under some circumstances, it will be useful to be able to have
a server's effective weight bigger than the user weight, and this
is particularly true for dynamic weight-based algorithms. In order
to support this, we add a "wdiv" member to the lbprm structure
which will always be used to divide the weights before reporting
them.
Since the introduction of server weights, all load balancing algorithms
relied on a pre-computed map. Incidently, quite a bunch of map-specific
parameters were used at random places in order to get the number of
servers or their total weight. It was not architecturally acceptable
that optimizations for the map computation had impact on external parts.
For instance, during this cleanup it was found that a backend weight was
seen as 1 when only the first backup server is used, whatever its weight.
This cleanup consists in differentiating between LB-generic parameters,
such as total weights, number of servers, etc... and map-specific ones.
The struct proxy has been enhanced in order to make it easier to later
support other algorithms. The recount_servers() function now also
updates generic values such as total weights so that it's not needed
anymore to call recalc_server_map() when weights are needed. This
permitted to simplify some code which does not need to know about map
internals anymore.
It is very convenient for SNMP monitoring to have unique process ID,
proxy ID and server ID. Those have been added to the CSV outputs.
The numbers start at 1. 0 is reserved. For servers, 0 means that the
reported name is not a server name but half a proxy (FRONTEND/BACKEND).
A remaining hidden "-" in the CSV output has been eliminated too.
This patch adds the "maxqueue" parameter to the server. This allows new
sessions to be immediately rebalanced when the server's queue is filled.
It's useful when session stickiness is just a performance boost (even a
huge one) but not a requirement.
This should only be used if session affinity isn't a hard functional
requirement but provides performance boost by keeping server-local
caches hot and compact).
Absence of 'maxqueue' option means unlimited queue. When queue gets filled
up to 'maxqueue' client session is moved from server-local queue to a global
one.
Hello,
This patch implements new statistics for SLA calculation by adding new
field 'Dwntime' with total down time since restart (both HTTP/CSV) and
extending status field (HTTP) or inserting a new one (CSV) with time
showing how long each server/backend is in a current state. Additionaly,
down transations are also calculated and displayed for backends, so it is
possible to know how many times selected backend was down, generating "No
server is available to handle this request." error.
New information are presentetd in two different ways:
- for HTTP: a "human redable form", one of "100000d 23h", "23h 59m" or
"59m 59s"
- for CSV: seconds
I believe that seconds resolution is enough.
As there are more columns in the status page I decided to shrink some
names to make more space:
- Weight -> Wght
- Check -> Chk
- Down -> Dwn
Making described changes I also made some improvements and fixed some
small bugs:
- don't increment s->health above 's->rise + s->fall - 1'. Previously it
was incremented an then (re)set to 's->rise + s->fall - 1'.
- do not set server down if it is down already
- do not set server up if it is up already
- fix colspan in multiple places (mostly introduced by my previous patch)
- add missing "status" header to CSV
- fix order of retries/redispatches in server (CSV)
- s/Tthen/Then/
- s/server/backend/ in DATA_ST_PX_BE (dumpstats.c)
Changes from previous version:
- deal with negative time intervales
- don't relay on s->state (SRV_RUNNING)
- little reworked human_time + compacted format (no spaces). If needed it
can be used in the future for other purposes by optionally making "cnt"
as an argument
- leave set_server_down mostly unchanged
- only little reworked "process_chk: 9"
- additional fields in CSV are appended to the rigth
- fix "SEC" macro
- named arguments (human_time, be_downtime, srv_downtime)
Hope it is OK. If there are only cosmetic changes needed please fill free
to correct it, however if there are some bigger changes required I would
like to discuss it first or at last to know what exactly was changed
especially since I already put this patch into my production server. :)
Thank you,
Best regards,
Krzysztof Oledzki
It is important to know how your installation performs. Haproxy masks
connection errors, which is extremely good for a client but it is bad for
an administrator (except people believing that "ignorance is a bless").
Attached patch adds retries and redispatches counters, so now haproxy:
1. For server:
- counts retried connections (masked or not)
2. For backends:
- counts retried connections (masked or not) that happened to
a slave server
- counts redispatched connections
- does not count successfully redispatched connections as backend errors.
Errors are increased only when client does not get a valid response,
in other words: with failed redispatch or when this function is not
enabled.
3. For statistics:
- display Retr (retries) and Redis (redispatches) as a "Warning"
information.
Removed old unused MODE_LOG and MODE_STATS, and replaced the "stats"
keyword in the global section. The new "stats" keyword in the global
section is used to create a UNIX socket on which the statistics will
be accessed. The client must issue a "show stat\n" command in order
to get a CSV-formated output similar to the output on the HTTP socket
in CSV mode.
A unix socket can now access the statistics. It currently only
recognizes the "show stat\n" command at the beginning of the
input, then returns the statistics in CSV format.
It is now possible to get CSV ouput from the statistics by
simply appending ";csv" to the HTTP request sent to get the
stats. The fields keep the same ordering as in the HTML page,
and a field "pxname" has been prepended at the beginning of
the line.
