[cover] Allow reconnection if node has been disconnected or down

OTP-10523

Earlier, if the connection to a remote cover node was lost, all cover
data was lost and the cover_server on the remote node would die. This
would cause problems if there were cover compiled modules that would
still be executed since they would attempt to write to the no longer
existing ets tables belonging to the cover_server.

This commit changes this behavior so that the cover_server on the
remote node will survive connection loss and continue collecting cover
data. If the connection is re-established then the main node will sync
with the remote node again and cover data will not be lost (unless the
node was down).

1 files changed, 5 insertions, 0 deletions

diff --git a/lib/tools/doc/src/cover.xml b/lib/tools/doc/src/cover.xml
index be0fd5bd47..a2444ec947 100644
--- a/lib/tools/doc/src/cover.xml
+++ b/lib/tools/doc/src/cover.xml
@@ -106,6 +106,11 @@
       from all nodes.</p>
     <p>To only collect data from remote nodes without stopping
       <c>cover</c> on those nodes, use <c>cover:flush/1</c></p>
+    <p>If the connection to a remote node goes down, the main node
+      will mark it as lost. If the node comes back it will be added
+      again. If the remote node was alive during the disconnected
+      periode, cover data from before and during this periode will be
+      included in the analysis.</p>
   </description>
   <funcs>
     <func>