Fsync all the things, all the time.

[chef.git] / cookbooks / planet / files / default / replication-bin / replicate-changesets

diff --git a/cookbooks/planet/files/default/replication-bin/replicate-changesets b/cookbooks/planet/files/default/replication-bin/replicate-changesets
index e35591e614d37ea56fa57d8b09779234cf9aac19..e71d4c5482aae3a861f250de6ddde77accafc870 100644 (file)
--- a/cookbooks/planet/files/default/replication-bin/replicate-changesets
+++ b/cookbooks/planet/files/default/replication-bin/replicate-changesets
@@ -15,6 +15,12 @@ CHANGES_LIMIT = 50000
 # this is the scale factor for lat/lon values stored as integers in the database
 GEO_SCALE = 10000000
 
+##
+# replace characters which cannot be represented in XML 1.0.
+def xml_sanitize(str)
+  str.gsub(/[\x00-\x08\x0b\x0c\x0e-\x1f]/, "?")
+end
+
 ##
 # changeset class keeps some information about changesets downloaded from the
 # database - enough to let us know which changesets are closed/open & recently
@@ -59,7 +65,7 @@ class ChangesetBuilder
     xml["num_changes"] = cs.num_changes.to_s
 
     res = @conn.exec("select u.id, u.display_name, c.min_lat, c.max_lat, c.min_lon, c.max_lon from users u join changesets c on u.id=c.user_id where c.id=#{cs.id}")
-    xml["user"] = res[0]["display_name"]
+    xml["user"] = xml_sanitize(res[0]["display_name"])
     xml["uid"] = res[0]["id"]
 
     unless res[0]["min_lat"].nil? ||
@@ -82,8 +88,8 @@ class ChangesetBuilder
     res = @conn.exec("select k, v from changeset_tags where changeset_id=#{cs.id}")
     res.each do |row|
       tag = XML::Node.new("tag")
-      tag["k"] = row["k"]
-      tag["v"] = row["v"]
+      tag["k"] = xml_sanitize(row["k"])
+      tag["v"] = xml_sanitize(row["v"])
       xml << tag
     end
   end
@@ -100,10 +106,10 @@ class ChangesetBuilder
     res.each do |row|
       comment = XML::Node.new("comment")
       comment["uid"] = row["author_id"]
-      comment["user"] = row["author"]
+      comment["user"] = xml_sanitize(row["author"])
       comment["date"] = Time.parse(row["created_at"]).getutc.xmlschema
       text = XML::Node.new("text")
-      text.content = row["body"]
+      text.content = xml_sanitize(row["body"])
       comment << text
       discussion << comment
     end
@@ -111,6 +117,27 @@ class ChangesetBuilder
   end
 end
 
+##
+# sync a file to guarantee it's on disk
+def fsync(f)
+  File.open(f) do |fh|
+    fh.fsync
+  end
+end
+
+##
+# sync a directory to guarantee it's on disk. have to recurse to the root
+# to guarantee sync for newly created directories.
+def fdirsync(d)
+  while d != "/"
+    Dir.open(d) do |dh|
+      io = IO.for_fd(dh.fileno)
+      io.fsync
+    end
+    d = File.dirname(d)
+  end
+end
+
 ##
 # state and connections associated with getting changeset data
 # replicated to a file.
@@ -180,9 +207,11 @@ class Replicator
       fl.flock(File::LOCK_EX)
 
       sequence = (@state.key?("sequence") ? @state["sequence"] + 1 : 0)
-      data_file = @config["data_dir"] + format("/%03d/%03d/%03d.osm.gz", sequence / 1000000, (sequence / 1000) % 1000, (sequence % 1000))
+      data_stem = @config["data_dir"] + format("/%03d/%03d/%03d", sequence / 1000000, (sequence / 1000) % 1000, (sequence % 1000))
+      data_file = data_stem + ".osm.gz"
+      data_state_file = data_stem + ".state.txt"
       tmp_state = @config["state_file"] + ".tmp"
-      tmp_data = "/tmp/changeset_data.osm.tmp"
+      tmp_data = data_file + ".tmp"
       # try and write the files to tmp locations and then
       # move them into place later, to avoid in-progress
       # clashes, or people seeing incomplete files.
@@ -195,8 +224,38 @@ class Replicator
         File.open(tmp_state, "w") do |fh|
           fh.write(YAML.dump(@state))
         end
+
+        # fsync the files in their old locations.
+        fsync(tmp_data)
+        fsync(tmp_state)
+
+        # sync the directory as well, to ensure that the file is reachable
+        # from the dirent and has been updated to account for any allocations.
+        fdirsync(File.dirname(tmp_data))
+        fdirsync(File.dirname(tmp_state))
+
+        # sanity check: the files we're moving into place
+        # should be non-empty.
+        raise "Temporary gzip file should exist, but doesn't." unless File.exist?(tmp_data)
+        raise "Temporary state file should exist, but doesn't." unless File.exist?(tmp_state)
+        raise "Temporary gzip file should be non-empty, but isn't." if File.zero?(tmp_data)
+        raise "Temporary state file should be non-empty, but isn't." if File.zero?(tmp_state)
+
         FileUtils.mv(tmp_data, data_file)
-        FileUtils.mv(tmp_state, @config["state_file"])
+        FileUtils.cp(tmp_state, @config["state_file"])
+        FileUtils.mv(tmp_state, data_state_file)
+
+        # fsync the files in their new locations, in case the inodes have
+        # changed in the move / copy.
+        fsync(data_fie)
+        fsync(@config["state_file"])
+        fsync(data_state_file)
+
+        # sync the directory as well, to ensure that the file is reachable
+        # from the dirent and has been updated to account for any allocations.
+        fdirsync(File.dirname(data_file))
+        fdirsync(File.dirname(@config["state_file"]))
+
         fl.flock(File::LOCK_UN)
 
       rescue
@@ -208,5 +267,10 @@ class Replicator
   end
 end
 
-rep = Replicator.new(ARGV[0])
-rep.save!
+begin
+  rep = Replicator.new(ARGV[0])
+  rep.save!
+rescue StandardError => e
+  STDERR.puts "ERROR: #{e.message}"
+  exit 1
+end