In the same way a stream has always valid conn-streams, when a health-checks
is created, a conn-stream is now created and the health-check is attached on
it, as an app. This simplify a bit the connect part when a health-check is
running.
cs_detach_app() function is added to detach an app from a conn-stream. And
now, both cs_detach_app() and cs_detach_endp() release the conn-stream when
both the app and the endpoint are detached.
Thanks to all previous changes, it is now possible to move the
stream-interface into the conn-stream. To do so, some SI functions are
removed and their conn-stream counterparts are added. In addition, the
conn-stream is now responsible to create and release the
stream-interface. While the stream-interfaces were inlined in the stream
structure, there is now a pointer in the conn-stream. stream-interfaces are
now dynamically allocated. Thus a dedicated pool is added. It is a temporary
change because, at the end, the stream-interface structure will most
probably disappear.
Because cs_detach() is releated to the endpoint only, the function is
renamed. The main purpose of this patch is to be able to add a function to
detach the conn-stream from the application.
To be able to move the stream-interface from the stream to the conn-stream,
all access to the SI is done via the conn-stream. This patch is limited to
the sink part.
To be able to move the stream-interface from the stream to the conn-stream,
all access to the SI is done via the conn-stream. This patch is limited to
the tcp-act part.
To be able to move the stream-interface from the stream to the conn-stream,
all access to the SI is done via the conn-stream. This patch is limited to
the httpclient part.
To be able to move the stream-interface from the stream to the conn-stream,
all access to the SI is done via the conn-stream. This patch is limited to
the http-act part.
To be able to move the stream-interface from the stream to the conn-stream,
all access to the SI is done via the conn-stream. This patch is limited to
the dns part.
To be able to move the stream-interface from the stream to the conn-stream,
all access to the SI is done via the conn-stream. This patch is limited to
the cache part.
To be able to move the stream-interface from the stream to the conn-stream,
all access to the SI is done via the conn-stream. This patch is limited to
the hlua part.
To be able to move the stream-interface from the stream to the conn-stream,
all access to the SI is done via the conn-stream. This patch is limited to
the debug part.
To be able to move the stream-interface from the stream to the conn-stream,
all access to the SI is done via the conn-stream. This patch is limited to
the peers part.
To be able to move the stream-interface from the stream to the conn-stream,
all access to the SI is done via the conn-stream. This patch is limited to
the proxy part.
To be able to move the stream-interface from the stream to the conn-stream,
all access to the SI is done via the conn-stream. This patch is limited to
the frontend part.
To be able to move the stream-interface from the stream to the conn-stream,
all access to the SI is done via the conn-stream. This patch is limited to
the log part.
To be able to move the stream-interface from the stream to the conn-stream,
all access to the SI is done via the conn-stream. This patch is limited to
the cli part.
To be able to move the stream-interface from the stream to the conn-stream, all
access to the SI is done via the conn-stream. This patch is limited to the
http-ana part.
To be able to move the stream-interface from the stream to the conn-stream,
all access to the SI is done via the conn-stream. This patch is limited to
the stream part.
To be able to move the stream-interface from the stream to the conn-stream,
all access to the SI is done via the conn-stream. This patch is limited to
the backend part.
To be able to move the stream-interface from the stream to the conn-stream,
all access to the SI is done via the conn-stream. This patch is limited to
the stream-interface part.
frontend and backend conn-streams are now directly accesible from the
stream. This way, and with some other changes, it will be possible to remove
the stream-interfaces from the stream structure.
In the same way the conn-stream has a pointer to the stream endpoint , this
patch adds a pointer to the application entity in the conn-stream
structure. For now, it is a stream or a health-check. It is mandatory to
merge the stream-interface with the conn-stream.
Because appctx is now an endpoint of the conn-stream, there is no reason to
still have the stream-interface as appctx owner. Thus, the conn-stream is
now the appctx owner.
Thanks to previous changes, it is now possible to set an appctx as endpoint
for a conn-stream. This means the appctx is no longer linked to the
stream-interface but to the conn-stream. Thus, a pointer to the conn-stream
is explicitly stored in the stream-interface. The endpoint (connection or
appctx) can be retrieved via the conn-stream.
To be able to handle applets as a conn-stream endpoint, we must be prepared
to handle different types of endpoints. First of all, the conn-strream's
connection must no longer be used directly.
Because the backend conn-stream is no longer released during connection
retry and because it is valid to have conn-stream with no connection, it is
possible to allocated it when the stream is created. This means, from now, a
stream has always valid frontend and backend conn-streams. It is the first
step to merge the SI and the CS.
The backend conn-stream is no longer released on connection retry. This
means the conn-stream is detached from the underlying connection but not
released. Thus, during connection retries, the stream has always an
allocated conn-stream with no connection. All previous changes were made to
make this possible.
Note that .attach() mux callback function was changed to get the conn-stream
as argument. The muxes are no longer responsible to create the conn-stream
when a server connection is attached to a stream.
si_attach_conn() function should be used to attach a connection to a
stream-interface. It created a conn-stream if necessary. This function is
mandatory to be able to keep the backend conn-stream during connection
retries.
si_reset_endpoint() function may be used to reset the SI's endpoint without
releasing the conn-stream if the endpoint is a connection. If the endpoint
is an appctx, it is released. This change is mandatory to merge the SI and
the CS and keep the backend conn-stream attached to the stream during
connection retries.
cs_detach() function is added to detach a conn-stream from the underlying
connection. This part will evovle to handle applets too. Concretely,
cs_destroy() is split to detach the conn-stream from its endpoint, via
cs_detach(), and then, the conn-stream is released, via cs_free().
In the same way the previous commit, when a stream is created, the appctx
case is now handled before the conn-stream one. The purpose of this change
is to limit bugs during the SI/CS refactoring.
The conn-stream will progressively replace the stream-interface. Thus, a
stream will have to allocate the backend conn-stream during its
creation. This means it will be possible to have a conn-stream with no
connection. To prepare this change, we test the conn-stream's connection
when we retrieve it.
Stream-interfaces will be moved in the conn-stream and the appctx will be
moved at the same level than the muxes. Idea is to merge the
stream-interface and the conn-stream and have a better symmetry between the
muxes and the applets. To limit bugs during this refactoring, when the SI
endpoint is released, the appctx case is handled first.
The pools currently have plenty of options (and some usefull ones were
even lost with the modern design), but most of them could be categorized
along a few use cases, namely, performance, reliability, debuggability.
This document explores various ways to try to combine them and their
effect in a less complex way for the long term.
This enables DEBUG_MEMORY_POOLS and DEBUG_POOL_INTEGRITY so that by
default the tests run under stricter checks, which are likely to
catch more bugs. Note that these ones are permanently used in prod
on haproxy.org.
The first one will enable all currently deployed BUG_ON() checks. These
ones are safe from a performance perspective and from a reliability
perspective. New ones may be added later with different categories
(hot path, detection of uncertain events, etc).
DEBUG_MEMORY_POOLS enables the "tag" pool debugging option by default,
so that pools may be better traced in dumps. This one alone results in
almost imperceptible performance difference, and 8 extra bytes per
allocated object.
Both options are safe for production use (they're among those enabled
all the time on haproxy.org) and allow to produce much more trustable
bug reports which should save a few round trips with the reporters.
The 9 currently available debugging options may now be checked, set, or
cleared using -dM. The directive now takes a comma-delimited list of
options after the optional poisonning byte. With "help", the list of
available options is displayed with a short help and their current
status.
The management doc was updated.
