On Tue, Mar 12, 2019 at 01:23:51PM +0530, Mithun Cy wrote: > I think pg_rewind's feature to rewind the promoted standby as a new > standby is broken in 11
Confirmed, it is. > Also I have tested same in version 10 it works fine there. > > Did below commit has broken this feature? (Thanks to kuntal for > identifying same) > commit 266b6acb312fc440c1c1a2036aa9da94916beac6 > Author: Fujii Masao <fu...@postgresql.org> > Date: Thu Mar 29 04:56:52 2018 +0900 > Make pg_rewind skip files and directories that are removed during server > start. And you are pointing out to the correct commit. The issue is that process_target_file() has added a call to check_file_excluded(), and this skips all the folders which it thinks can be skipped. One problem though is that we also filter out pg_internal.init, which is present in each database folder, and remains in the target directory marked for deletion. Then, when the deletion happens, the failure happens as the directory is not fully empty. We could consider using rmtree() instead, but it is a nice sanity check to make sure that all the entries in a path have been marked for deletion. Just removing the filter check on the target is fine I think, as we only should have the filters anyway to avoid copying unnecessary files from the source. Attached is a patch. What do you think? (check_file_excluded() could be simplified further but it's also nice to keep some mirroring in this API if we finish by using it for target files at some point.) -- Michael
diff --git a/src/bin/pg_rewind/filemap.c b/src/bin/pg_rewind/filemap.c index bb4ffd0e38..a2cd317c72 100644 --- a/src/bin/pg_rewind/filemap.c +++ b/src/bin/pg_rewind/filemap.c @@ -334,12 +334,11 @@ process_target_file(const char *path, file_type_t type, size_t oldsize, file_entry_t *entry; /* - * Ignore any path matching the exclusion filters. This is not actually - * mandatory for target files, but this does not hurt and let's be - * consistent with the source processing. + * Do not apply any exclusion filters here, the folders marked for + * deletion on the target should be entirely empty, and we also + * check after pg_internal.init which is present in each database + * folder. */ - if (check_file_excluded(path, false)) - return; snprintf(localpath, sizeof(localpath), "%s/%s", datadir_target, path); if (lstat(localpath, &statbuf) < 0)
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