That depends on what you consider more important. Since your logging service (Graylog) is stuck, that means your module can do the following:
* Stall and queue up logs until the logging service is unstuck. * Drop logs. * Log to some other location/service. Basically, it is up to you whether you want to keep logs or keep your services healthy, albeit without logs. For a centralized logging service like Graylog, it is usually a good idea to set up your logging pipeline in three components: Your tasks + your logging module => log forwarding service located on the same machine/node => log aggregation server(s) Since the log forwarding service is co-located, it is much less likely for that service to stall. And when there is a network partition, or if the upstream aggregation server stalls, it is up to the forwarding service to buffer the logs and remain responsive. On Wed, Jun 7, 2017 at 8:49 PM, liang tang <liangtang20080...@gmail.com> wrote: > I think > https://github.com/apache/mesos/blob/master/src/slave/ > containerizer/mesos/io/switchboard.cpp#L278-L289 > is the real entry where prepare function in container logger will be > invoked. > > I wrote a module which sends stderr and stdout to graylog. If graylog got > stuck, service in Marathon even cannot run successfully, at the same time > we cannot kill the stuck task in Marathon. > > How can I deal with the stuck process in mesos module not having any bad > effect on mesos services? > > > > 2017-06-02 9:35 GMT+08:00 Joseph Wu <jos...@mesosphere.io>: > > > 1) The entry point for the container logger module is here: > > https://github.com/apache/mesos/blob/1.3.x/src/slave/ > > container_logger.cpp#L42-L52 > > > > All modules have a "create" method which attempts to load the dynamic > > library containing the module. The --modules flag you specify at > > agent/master startup time tells the agent/master where to find the > library > > and what the symbol name to load is. > > > > For other invocations of the module(s), you'll need to look for places in > > the code where the module interface is called. The precise module class > > obviously won't be referenced directly within the codebase (because > they're > > loaded at runtime, rather than at compile time). > > > > 2) Modules are loaded precisely so that they have an influence > (otherwise, > > why load a module at all?). If you don't like the side effects of a > > module, your choices are to either disable the module, or to tweak the > > module yourself and reload it. > > > > > > On Tue, May 30, 2017 at 8:38 PM, liang tang <liangtang20080...@gmail.com > > > > wrote: > > > > > 1. Cannot find mesos module entry where module will start to run? > didn't > > > find in slave/main.cc or module/mananger.cc > > > > > > 2. Why process in mesos module exits, service cannot be run in > Marathon? > > > In my option, module shouldn't have an influence on service running. > > > > > > Which code will invoke code about container logger module in > > > https://github.com/apache/mesos/blob/master/src/slave/ > > > container_loggers/lib_logrotate.cpp#L309-L339 > > > > > > > > > > > > mesos::modules::Module<ContainerLogger> > > > org_apache_mesos_LogrotateContainerLogger( > > > MESOS_MODULE_API_VERSION, > > > MESOS_VERSION, > > > "Apache Mesos", > > > "modules@mesos.apache.org", > > > "Logrotate Container Logger module.", > > > nullptr, > > > [](const Parameters& parameters) -> ContainerLogger* { > > > // Convert `parameters` into a map. > > > std::map<std::string, std::string> values; > > > foreach (const Parameter& parameter, parameters.parameter()) { > > > values[parameter.key()] = parameter.value(); > > > } > > > > > > // Load and validate flags from the map. > > > mesos::internal::logger::Flags flags; > > > Try<flags::Warnings> load = flags.load(values); > > > > > > if (load.isError()) { > > > LOG(ERROR) << "Failed to parse parameters: " << load.error(); > > > return nullptr; > > > } > > > > > > // Log any flag warnings. > > > foreach (const flags::Warning& warning, load->warnings) { > > > LOG(WARNING) << warning.message; > > > } > > > > > > return new mesos::internal::logger::LogrotateContainerLogger( > > flags); > > > }); > > > > > >
