> On Sept. 19, 2015, 6:57 a.m., Cong Wang wrote: > > Why not just set --host_name=$LIBPROCESS_IP for your case since you anyway > > need to provide a flag? > > Guangya Liu wrote: > I also have the same question with Cong, @Marco, can you please show more > detail for why not using the solution as above? What is the benefit of this > compared to using --host_name=$LIBPROCESS_IP? Thanks. > > Marco Massenzio wrote: > `$LIBPROCESS_IP` may not be set by the time we run the binary - it is > actually set in the `main()` method (of both Master/Agent) after parsing the > `--ip` (and `--ip_discovery_command`) flags. > > The reason I use `LIBPROCESS_IP` here is to ensure that the IP used by > `libprocess` (which is initialized before creating the `Master` or `Slave` > object) is consistent with what the `Master/Agent` will be configured with. > > Please also refer to the conversation about the introduction of > `--ip_discovery_command` as to why we need a "dynamic" way of configuring > hostname/IP - it all boils down to make Mesos play nice in various Cloud (and > Enterprise data centers) where the DNS resolution (and hostname configuration > of VMs) is vastly different and may not necessarily conform to the generally > assumed scenario, where IP/hostname are kept in sync / resolved by the OS > and/or external services (DHCP/DNS).
If you want to set hostname to the chosen IP, then I think you can just use the existing flag "--hostname" (set it to the chosen IP manually). And if "--hostname" is set, then I think the hostname lookup will be bypassed. So why do we need to introduce a new flag "--no_hostname_lookup"? - Qian ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/38473/#review99628 ----------------------------------------------------------- On Sept. 19, 2015, 9:25 a.m., Marco Massenzio wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/38473/ > ----------------------------------------------------------- > > (Updated Sept. 19, 2015, 9:25 a.m.) > > > Review request for mesos, Benjamin Hindman, Cody Maloney, and Neil Conway. > > > Bugs: MESOS-3457 > https://issues.apache.org/jira/browse/MESOS-3457 > > > Repository: mesos > > > Description > ------- > > Under certain circumstances, dynamic lookup of hostname, while > successful, provides undesirable results; we would also like, in > those circumstances, be able to just set the hostname to the chosen > IP address (possibly set via the --ip_discovery_command method). > > The flag we add here, --[no]-hostname_lookup is `true` by default > (which is the existing behavior) and will work under most > circumstances: however, by disabling lookup (using, for example, > --no_hostname_lookup) the hostname used will be the same as the > one configured (possibly, via --ip or MESOS_IP) in `LIBPROCESS_IP`. > > This change affects both Master/Agent nodes. > > WARNING - the `Address::hostname()` method always does a dynamic > hostname lookup, which may in fact return inconsistent results > wrt the Master's configuration (this is *not* affected by > this change) and should be avoided; use instead > `Master::info()::hostname()` which is always consistent with > the Master's configuration. > > > Diffs > ----- > > docs/configuration.md dd7f4aa806a3c1a8653a0fda9a326a3707308e7c > src/master/flags.hpp e4b1df3f5a33049defff4688463274067f1f1ebf > src/master/flags.cpp 80879611fbcfd764c9fc8f60a31613a9c8fc2364 > src/master/master.cpp ca4d5876dcd427964111428edc22d567ddaede0b > src/slave/flags.hpp e31a4183170c3442ac4a15365c229391e7e91480 > src/slave/flags.cpp add4196dfd06c0f602ff5ebd39960dc05c4cd11f > src/slave/slave.cpp ad710d7b930a2f115d503ceb8f8fd7421ad30287 > src/tests/cluster.hpp 114583de8c867495a2b7a953e6826708838e5d23 > src/tests/master_tests.cpp a477794df37c658b80d79dea8555b001415f7b6a > src/tests/mesos.hpp 3db97aca921c9216d90384e1eb17030849516454 > > Diff: https://reviews.apache.org/r/38473/diff/ > > > Testing > ------- > > make check > > > Thanks, > > Marco Massenzio > >
