-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 After a discussion with Mathieu and Yannick, here is some big changes.
I hope I did not forget anything important. Cheers! David -----BEGIN PGP SIGNATURE----- iQEcBAEBCgAGBQJQIWfcAAoJEELoaioR9I02SAkH/iic+EYwOs5dw0X+yS37sBrp rbP8VHm+v7OP4Lc+x84pfHBnz0pk5qM7MN5/lmMpRfRwCiYNW8CbxC13V5Au6UgC PsNQdZGduVb56xmB5zhV1cD1laiU2W+0vdQzahIN0YDDZowYa6uJda9yjav/b6z8 +duI2Zuw9NPOUnIDCSIpb3hKA4NZIZFsQGn+/IToikqWyRt/4wwiufaZNtlC85/w C0pGJL/9TBTY4rFmyZ/e19lJRUoNEygrFRRoJb5qxKWH5nHvfRXdFGw78xjDgim7 g9AvrWZ7g73KZaS7LEpmAcofgRicWafIMd0+jUXv0MMrj3NeT/xD66UbtcUusl8= =jRvr -----END PGP SIGNATURE-----
RFC - LTTng address API proposal Author: David Goulet <[email protected]> Contributors: * Mathieu Desnoyers <[email protected]> * Yannick Brosseau <[email protected]> Version: - v0.1: 31/07/2012 * Initial proposal - v0.2: 07/08/0212 * Remove lttng_create_session_addr * Describe URL string format * Add set_consumer_url examples Introduction ----------------- This document proposes the use of string URLs to the command line interface and API which will deprecate a function and propose new ones. The purpose of this proposal is to support network streaming using URL string format that you can find in proposal doc/proposals/0003-network.consumer.txt, remove the lttng_uri structure from the API and integrate the URL string to the API. API ----------------- In order NOT to expose the new lttng_uri structure used to identify trace location for lttng consumer, the public API will only use string address where it will be converted in a lttng_uri and sent to the session daemon. [*] Create session: With the introduction of the enable-consumer command used for network streaming, the create session command has been modified so the user could define a consumer location either on the network or local with the command. This does NOT change the current API call but rather simply rename _path_ to _url_ and how it is used in the lttng-ctl library. Call changed from: --> lttng_create_session(const char *name, const char *path); To: --> lttng_create_session(const char *name, const char *url); The _name_ argument is the session name and _url_ is a string representing the URL specified by the user which is define like so: PROTO://[HOSTNAME|IP][:PORT][/PATH] The proto supported at this stage are (6 means IPv6): * net, net6, tcp, tcp6, file If the proto is NOT recognized, the string is considered to be a simple path on the local filesystem. The PATH section is the destination path on the _remote_ host where the trace data will be written with the <target_hostname> append after. The relayd defines a default location if none is given using the -o, --output option. This default is at: * $USER/lttng-traces For example, this URL results in writing the trace data in "$USER/lttng-traces/<target_hostname>/foo/bar". * net://hostname/foo/bar The PATH part can not be bigger than PATH_MAX (define in limits.h) which is 4096 bytes at the time of this proposal. Moreover, "../" is ignored and removed. For instance, using "net://localhost/../../" will set the path to the default one. The <net(6)> protocol has a special case where the user can input two ports respectively being the control and data port. * net://[HOSTNAME|IP][:CTRL_PORT][:DATA_PORT][/PATH] If _url_ is not NULL, the lttng_create_session will use two API calls. 1) lttng_set_consumer_url(handle, url); 2) lttng_enable_consumer(handle); If _url_ is NULL, then NO consumer is created for this tracing session and subsequent calls are needed to set up a consumer (i.e lttng_enable_consumer and lttng_set_consumer_url). [*] Consumer: This call is simply renamed. From: --> lttng_set_consumer_uri(...) To: --> lttng_set_consumer_url(struct lttng_handle *handle, const char *url); For both functions (consumer and create), the _url_ will be parsed into a lttng_uri in the liblttng-ctl and sent to the session daemon. Example: lttng_set_consumer_url(handle, "net://42.42.42.2"); With all this, the lttng_uri data structure will NOT be exposed to the public API and the user command line interface.
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