Update configuration of compaction daemon

[adrienverge]

Fix default check_interval value in compaction docs

Since apache/couchdb@58fef34 "feat: bump the compaction daemon
check_interval to one hour", the default value is 3600.

---

Try to make check_interval explanation clearer

We had a hard time finding whether check_interval was waited between
each database compaction, or between a whole compaction run for all
databases.

I propose to make it very explicit.

---

Add missing snooze_period_ms in compaction docs

This new parameter was introduced in apache/couchdb@e5bf9d4 "add
snooze_period doc to default.ini" and changed in apache/couchdb@5471694
"Add snooze_period_ms for finer tuning".

[adrienverge]

I just updated the third commit to take the merge of apache/couchdb#1880 into account:

--- a/src/config/compaction.rst
+++ b/src/config/compaction.rst
@@ -172,16 +172,19 @@ Configuration of Compaction Daemon
             [compaction_daemon]
             min_file_size = 131072
 
-    .. config:option:: snooze_period
+    .. config:option:: snooze_period_ms
 
         With lots of databases and/or with lots of design docs in one or more
         databases, the compaction_daemon can create significant CPU load when
         checking whether databases and view indexes need compacting. The
-        snooze_period setting ensures a smoother CPU load. Defaults to
-        3 seconds wait.
+        ``snooze_period_ms`` setting ensures a smoother CPU load. Defaults to
+        3000 milliseconds wait. Note that this option was formerly called
+        ``snooze_period``, measured in seconds (it is currently still
+        supported).
 
             [compaction_daemon]
-            snooze_period = 3
+            snooze_period_ms = 3000
+
 
 .. _config/view_compaction:

[jiangphcn]

just double check, the default for snooze_period_ms is 3600 instead of 3000?

[adrienverge]

No the default is 3000 milliseconds (i.e. 3 seconds).

[jiangphcn]

then you may want to add snooze_period_ms around https://github.com/apache/couchdb-documentation/pull/386/files#diff-2942fe0bd584dca8819c4c3c22f3504bR184?

[adrienverge]

I pasted the diff but forgot to push... sorry about that and thanks for telling me!

[jiangphcn]

Cool. There is one failure from travis. Could you please check?

[adrienverge]

Sure, done!

[wohali]

Approved with minor changes, please revise

[adrienverge]

Updated:

--- a/src/config/compaction.rst
+++ b/src/config/compaction.rst
@@ -157,7 +157,7 @@ Configuration of Compaction Daemon
     .. config:option:: check_interval
 
         The delay, in seconds, between each check for which database and view
-        indexes need to be compacted. In other words, this delay will be waited
+        indexes need to be compacted. In other words, this delay will occur
         after *all* databases and views are compacted (or at least checked)::
 
             [compaction_daemon]
@@ -178,9 +178,7 @@ Configuration of Compaction Daemon
         databases, the compaction_daemon can create significant CPU load when
         checking whether databases and view indexes need compacting. The
         ``snooze_period_ms`` setting ensures a smoother CPU load. Defaults to
-        3000 milliseconds wait. Note that this option was formerly called
-        ``snooze_period``, measured in seconds (it is currently still
-        supported).
+        3000 milliseconds wait.
 
             [compaction_daemon]
             snooze_period_ms = 3000

[wohali]

Thanks @adrienverge !