From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from simark.ca by simark.ca with LMTP id lsHeCWR9J2JfOgAAWB0awg (envelope-from ) for ; Tue, 08 Mar 2022 10:59:32 -0500 Received: by simark.ca (Postfix, from userid 112) id 17BD71F3CA; Tue, 8 Mar 2022 10:59:32 -0500 (EST) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on simark.ca X-Spam-Level: X-Spam-Status: No, score=-3.0 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.2 Received: from lists.lttng.org (lists.lttng.org [167.114.26.123]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by simark.ca (Postfix) with ESMTPS id 8AE3C1F0D2 for ; Tue, 8 Mar 2022 10:59:31 -0500 (EST) Received: from lists-lttng01.efficios.com (localhost [IPv6:::1]) by lists.lttng.org (Postfix) with ESMTP id 4KCg4g1Jvkz95D; Tue, 8 Mar 2022 10:59:31 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=lists.lttng.org; s=default; t=1646755171; bh=bw9SUVOmqG51dWmuUkJPJBRvgxBSGDd5dSciy/SiKqs=; h=Date:To:Cc:Subject:List-Id:List-Unsubscribe:List-Archive: List-Post:List-Help:List-Subscribe:From:Reply-To:From; b=zDUStu+++wbdroplibOjO1GnNnoJXI6z6yrxijEwu8SlqG1sPoekJCgYg2NeoyWd4 xxvp8THDhbB+lMhr7WhuyTyxCimFXdKC9UsRjs0Xxoyq94GfFJogu/aQeFuWonCdI5 7dTBmb6crkEJgn8qzBxjAXJ/tkT8k7HuTJYf6i5wZ7b8n3+v0Huvo3Ietnx9bshcRU g2xJXeU2m8Pk8fDj98s+T+AEj0n7BB/dICBEXdKi3ihkr8YqH82IP5B9glTuyhxBQ8 16BvdCE8t9PTCXLIOfTCBsuTSKQHu+11jClq2+/KAUP1XdSTqmh32MDl8zQqFtQRcZ gIEeonEl3P7ow== Received: from mail.efficios.com (mail.efficios.com [167.114.26.124]) by lists.lttng.org (Postfix) with ESMTPS id 4KCg4d4FRhz9SG for ; Tue, 8 Mar 2022 10:59:29 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mail.efficios.com (Postfix) with ESMTP id 060D9367F22 for ; Tue, 8 Mar 2022 10:59:23 -0500 (EST) Received: from mail.efficios.com ([127.0.0.1]) by localhost (mail03.efficios.com [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id BaGnnBjD7vdP; Tue, 8 Mar 2022 10:59:22 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mail.efficios.com (Postfix) with ESMTP id 85FFB367EA5; Tue, 8 Mar 2022 10:59:22 -0500 (EST) DKIM-Filter: OpenDKIM Filter v2.10.3 mail.efficios.com 85FFB367EA5 X-Virus-Scanned: amavisd-new at efficios.com Received: from mail.efficios.com ([127.0.0.1]) by localhost (mail03.efficios.com [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id xmdKTYp-sI5Z; Tue, 8 Mar 2022 10:59:22 -0500 (EST) Received: from mail03.efficios.com (mail03.efficios.com [167.114.26.124]) by mail.efficios.com (Postfix) with ESMTP id 76EF43677FD; Tue, 8 Mar 2022 10:59:22 -0500 (EST) Date: Tue, 8 Mar 2022 10:59:22 -0500 (EST) To: diamon-discuss Cc: lttng-dev , tracecompass-dev Message-ID: <270093074.129957.1646755162428.JavaMail.zimbra@efficios.com> MIME-Version: 1.0 X-Originating-IP: [167.114.26.124] X-Mailer: Zimbra 8.8.15_GA_4203 (ZimbraWebClient - GC97 (Linux)/8.8.15_GA_4232) Thread-Index: FVtoLdTTkTyaKSQFMfO7fn7womzHxA== Thread-Topic: CTF 2: removal of the JSON text sequence auxiliary stream feature Subject: [lttng-dev] CTF 2: removal of the JSON text sequence auxiliary stream feature X-BeenThere: lttng-dev@lists.lttng.org X-Mailman-Version: 2.1.39 Precedence: list List-Id: LTTng development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Philippe Proulx via lttng-dev Reply-To: Philippe Proulx Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: lttng-dev-bounces@lists.lttng.org Sender: "lttng-dev" Hello, Upon reflection, the JSON text sequence auxiliary streams of CTF2-SPECRC-4.0 [1] and data streams are redundant concepts considering that a CTF 2 data stream class may have a namespace and a name to identify it as containing specific/auxiliary data. Moreover, using data streams to transport "auxiliary" data means: * Simpler implementation within existing CTF 1.8 tools: they can already read and/or write data streams. This means faster CTF 2 adoption. * Simpler CTF 2 specification (JSON text sequence auxiliary stream concept is removed). * More compact streams containing auxiliary data out of the box. * A producer may attach user attributes to a data stream. Note that if a data stream doesn't need a default clock, then its class simply needs to not have any default clock class. This makes it possible to have event records only containing data, without timing information. The only lost benefit of not using JSON text sequence auxiliary streams is not being able to read one without a CTF 2 data stream decoder. However, I believe there's little point in doing so without having access to a complete CTF 2 consumer to process the trace further anyway. Considering all of the above, I'm about to release CTF2-SPECRC-5.0 which removes the JSON text sequence auxiliary stream feature. To remain backward compatible with CTF 1.8, however, CTF2-SPECRC-5.0 will specify a data stream class (having the `std` namespace) and event record classes to make a data stream contain the trace environment (`env` block in TSDL). CTF 2 might also specify some "hidden" user attribute in the future to indicate that a consumer should not display the instances of a given data stream class. Indeed, should a data stream contain a symbol map, for example, we don't want such data to show up in the output of a Babeltrace 2 `sink.text.pretty` component or in the events editor of Trace Compass. Should you have any issue with this approach, please reply to this email to illustrate your point of view. Have a good day, Philippe Proulx EfficiOS Inc. https://www.efficios.com/ _______________________________________________ lttng-dev mailing list lttng-dev@lists.lttng.org https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev