-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Hi, I'll add to this:
W dniu 17.02.2016 o 14:56, Zbigniew Jędrzejewski-Szmek pisze: > On Wed, Feb 17, 2016 at 02:35:55PM +0200, Avi Kivity wrote: >> We are using systemd to supervise our NoSQL database and are >> generally happy. >> >> A few things will help even more: >> >> 1. log core dumps immediately rather than after the dump >> completes >> >> A database will often consume all memory on the machine; dumping >> 120GB can take a lot of time, especially if compression is >> enabled. As the situation is now, there is a period of time where >> it is impossible to know what is happening. >> >> (I saw that 229 improves core dumps, but did not see this >> specifically) > > The coredump is logged afterwards because that's the only way to > include all information (including the compressed file name) in > one log message. But there are two changes which might mitigate the > problem: - semi-recently we switched to lz4, which compresses > significantly faster, have you tried that? > > - recently the responsibility of writing core dumps was split out > to a service. I'm not sure how that influences the time when the > log message is written. > >> 2. parallel compression of core dumps >> >> As well as consuming all of memory, we also consume all cpus. >> Once we dump core we may as well use those cores for compressing >> the huge dump. > > This should be implemented in the compression library. The > compressor does not seem to be threaded, but it was we would try to > make use of it. OTOH, single-threaded lz4 is able to produce > ~500MB/s of compressed output, so you'd need a really fast disk to > go above that. > >> 3. watchdog during startup >> >> Sometimes we need to perform expensive operations during startup >> (log replay, rebuild from network replica) before we can start >> serving. Rather than configure a huge start timeout, I'd prefer >> to have the service report progress to systemd so that it knows >> that startup is still in progress. This requires cooperation from the service process, but is probably possible. > > Zbyszek _______________________________________________ > systemd-devel mailing list systemd-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/systemd-devel > -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJWxICYAAoJEHb1CzgxXKwYDooP/2OAx9WYfFuKDDrtuQ4KNRi/ X+20724fBeSJ7NZs/JieLjVYwAIRkHD/5OXzW2S5HZAvilrQwUCiSCZfADNB+0Tv 189noHuR4l9PopMUoVl4ay13W+1O93x2Tq3SPxe0SmkQEl9tWzKYYeS98q80a5gE 179fvQtkyDfcoKLp5npxmXaQZpqarl6FH3z41hHzWJdTZKiOiAFtYYSxNgzDRvar cBGSTsb8NLGMZBA0B0NLGWNNLMIq2qZbIJ600I1Buu6OkBGq0dyikFUpEdWdW8+k SVOGLrNll8wxpzd8Kxm9CmoQmzw/Bgo9eeX2kpuubOd85IBfauI/vzpTXw4geWzw PuMh9NetEWpNTx6fqbpJ+yVSygldJ1HRKeTjmM6kt527D8yRvNOGdsQEgzqxi1l3 3aWohll4FDL0f5CpnCixZH8ZNwTePIacQi3Btd76LK9m8Fu4cV9yi70L4tY6dewQ 7XZEYK77s4p8R5UpyGsx2X/rtkZI6nGNRejWSzkAfsLBb0VL5TxqJyw5goP+ATIZ HDJz8pPN2hxDLzQ9ou70sG1O3Pt87dF4BjHqWCeoMKQJ8Z0LfhlLz44EVX/EYfjy 0A298GlPgw+Jhb8lm3e/eFnbfl3iHYaQmtewXwOhcSKfHB13TGAkPwW6YTFafVDG JDjiS2mB3v4ONwuu2gCs =S4f+ -----END PGP SIGNATURE----- _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/systemd-devel
