This will simply cause a task to be posted to each worker.
If the workers are running normally, the task will reach the
workers and the associated semaphore posted, and the REST-API
call will return. If any worker is not running normally, the
task will not be processed and the REST-API call will hang.
As the router is the only one that knows what backends a particular
statement has been sent to, it is the responsibility of the router
to keep the session bookkeeping up to date. If it doesn't we will
know what statements a session has received (provided at least some
component in the routing chain has RCAP_TYPE_STMT_INPUT capability),
but not how long their processing took. Currently only readwritesplit
does that.
All queries are stored and not just COM_QUERY as that makes the
overall bookkeeping simpler; at clientReply() time we do not need to
know whether or not to bookkeep information, we can just do it.
When session information is queried for, we report as much information
we have available.
This commit introduces the plumbing support for obtaining
classification information of a statement using the REST-API.
It introduces a URL like
/v1/maxscale/query_classifier/classify?sql=SELECT+1
that in the response will return a JSON object with the
information. Subsequent commits will provide the actual
information.
Fix comments.
Fix a bug in make_valid().
Change sync time (when the average should be pushed to the server EMA)
to only depend on time, not use sample_max. This decreases the amount of
sync calls, and allows for a much shorter sync time. Testing shows this to be
more stabel and allows to make sample_max adaptive .
Fix comments.
Fix a bug in make_valid().
Change sync time (when the average should be pushed to the server EMA)
to only depend on time, not use sample_max. This decreases the amount of
sync calls, and allows for a much shorter sync time. Testing shows this to be
more stabel and allow better control of the sample_max.
The reads now read as much of the data as is available to reduce the
number of distinct malloc calls that need to be made. The SSL_read also
now allocates the buffer before reading into it so that the amount of
copying is reduced.
Also removed some of the not quite helpful debug messages.
The client connections had the Nagle algorithm enabled which could cause
bad performance with smaller workloads. The common network configuration
code in utils.cc, currently used by the backend connections, sets it
properly.
Replaced SPINLOCK with std::mutex where possible, leaving out the more
complex cases. The big offenders remaining are the binlogrouter and the
gateway.cc OpenSSL locks.
In progress, does not yet overwrite existing code.
The new promotion mechanism automatically retries queries which timed out. It also
handles multimaster situations correctly.
Removed the almost equal comparison and subsequent selection based on historical number of connections.
The effect of it was this: Select the server that has historically, weights or not, been slower. Tested this with 2.2
with maxscale on one server and mariadb:s on two servers with different network lags. The tests with historical
selects were clearly slower.
The schemarouter now uses the RWBackend to track the response states. This
fixes the debug assertions that happened with the mxs1113_schemarouter_ps
test.
By splitting the processing and state querying into two separate
functions, the result can be inspected multiple times without triggering
the result processing.
Added `match` and `exclude` functionality. This allows versatile filtering
without a large investment of development time by leveraging the benefits
of PCRE2 regular expressions.
Also cleaned up the filter and removed the single table matching and
active parameter that were obsoleted by the regular expression parameters.
The read-write distribution in readwritesplit is now stored in a map
partitioned by the servers that the router has used. Currently, the
statistics for removed servers aren't dropped so some filtering still
needs to be added.
The statistic.hh header defines a set of functions that complement the
standard library numeric functions. They differ from the standard library
functions in that they take a container reference and a pointer-to-member
as parameters and calculate the statistic based on the pointed-to member.
The additions into the server.h header used C++ language which caused C
programs to fail to compile. Moved the implementation of the EMAverage
class into the private Server class in the server.hh header and exposed it
via functions in the server.h header. Also temporarily moved
almost_equal_server_scores into the public server.hh as there is no
service.hh header.
See script directory for method. The script to run in the top level
MaxScale directory is called maxscale-uncrustify.sh, which uses
another script, list-src, from the same directory (so you need to set
your PATH). The uncrustify version was 0.66.
Changes that allow slow or new servers to quickly apply samples towards the
server average. The most important changes are to not ignore the first N samples,
and apply an average to the server as soon as there is one available.
The new ResponseStat::make_valid() will use filter samples to add an average,
if no averages have yet been added, even if the number of filter samples is less
than the filter limit.
The math becomes simpler when the weight is inverted, i.e. a simple multiplication
to get the (inverse) score. Inverse weights are normalized to the range [0..1] where a lower
number is a higher weight,
The enum select_criteria_t is used to provide a std::function that takes the backends
as vector (rather than the prior pairwise compares) and returns the best backend.
