module Resque::Pool::Logging
Constants
- PROCLINE_PREFIX
Public Class Methods
reopen_logs!()
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This reopens ALL logfiles in the process that have been rotated using logrotate(8) (without copytruncate) or similar tools. A File
object is considered for reopening if it is:
1) opened with the O_APPEND and O_WRONLY flags 2) the current open file handle does not match its original open path 3) unbuffered (as far as userspace buffering goes, not O_SYNC)
Returns the number of files reopened
This was mostly copied from Unicorn 4.8.2 to simplify reopening logs in the same way that Unicorn does. Original comments and explanations are left intact.
# File lib/resque/pool/logging.rb, line 17 def self.reopen_logs! to_reopen = [ ] reopened_count = 0 ObjectSpace.each_object(File) { |fp| is_log?(fp) and to_reopen << fp } log "Flushing #{to_reopen.length} logs" to_reopen.each do |fp| orig_st = begin fp.stat rescue IOError, Errno::EBADF # race next end begin b = File.stat(fp.path) # Skip if reopening wouldn't do anything next if orig_st.ino == b.ino && orig_st.dev == b.dev rescue Errno::ENOENT end begin # stdin, stdout, stderr are special. The following dance should # guarantee there is no window where `fp' is unwritable in MRI # (or any correct Ruby implementation). # # Fwiw, GVL has zero bearing here. This is tricky because of # the unavoidable existence of stdio FILE * pointers for # std{in,out,err} in all programs which may use the standard C library if fp.fileno <= 2 # We do not want to hit fclose(3)->dup(2) window for std{in,out,err} # MRI will use freopen(3) here internally on std{in,out,err} fp.reopen(fp.path, "a") else # We should not need this workaround, Ruby can be fixed: # http://bugs.ruby-lang.org/issues/9036 # MRI will not call call fclose(3) or freopen(3) here # since there's no associated std{in,out,err} FILE * pointer # This should atomically use dup3(2) (or dup2(2)) syscall File.open(fp.path, "a") { |tmpfp| fp.reopen(tmpfp) } end fp.sync = true fp.flush # IO#sync=true may not implicitly flush new_st = fp.stat # this should only happen in the master: if orig_st.uid != new_st.uid || orig_st.gid != new_st.gid fp.chown(orig_st.uid, orig_st.gid) end log "Reopened logfile: #{fp.path}" reopened_count += 1 rescue IOError, Errno::EBADF # not much we can do... end end reopened_count end
Private Class Methods
is_log?(fp)
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Used by reopen_logs, borrowed from Unicorn…
# File lib/resque/pool/logging.rb, line 111 def self.is_log?(fp) append_flags = File::WRONLY | File::APPEND ! fp.closed? && fp.stat.file? && fp.sync && (fp.fcntl(Fcntl::F_GETFL) & append_flags) == append_flags rescue IOError, Errno::EBADF false end
Public Instance Methods
app()
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Include optional app name in procline
# File lib/resque/pool/logging.rb, line 102 def app app_name = self.respond_to?(:app_name) && self.app_name app_name ||= self.class.respond_to?(:app_name) && self.class.app_name app_name ? "[#{app_name}]" : "" end
log(message)
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TODO: make this use an actual logger
# File lib/resque/pool/logging.rb, line 88 def log(message) return if $skip_logging puts "resque-pool-manager#{app}[#{Process.pid}]: #{message}" #$stdout.fsync end
log_worker(message)
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TODO: make this use an actual logger
# File lib/resque/pool/logging.rb, line 95 def log_worker(message) return if $skip_logging puts "resque-pool-worker#{app}[#{Process.pid}]: #{message}" #$stdout.fsync end
procline(string)
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Given a string, sets the procline ($0) Procline is always in the format of:
resque-pool-master: STRING
# File lib/resque/pool/logging.rb, line 83 def procline(string) $0 = "#{PROCLINE_PREFIX}#{app}: #{string}" end