### 3. Backup Existing System

Before migration:

1. Export current search configurations
2. Backup existing indices and data
3. Document custom integrations and API endpoints
4. Save user access control settings

---

## Migration Methods

### Google Search Appliance (GSA) / Google Mini

Fess provides comprehensive GSA migration support through configuration import and API compatibility.

   * filters to be compatible, they must:
   *
   * <ul>
   *   <li>not be the same instance
   *   <li>have the same number of hash functions
   *   <li>have the same bit size
   *   <li>have the same strategy
   *   <li>have equal funnels
   * </ul>
   *
   * @param that The Bloom filter to check for compatibility.
   * @since 15.0
   */

		hex.EncodeToString(x.Signature[:]),
		time.Unix(0, x.ModTime),
		x.Flags.String(),
		x.EcN, x.EcM,
	)
}

// matchesNotStrict returns whether x and o have both have non-zero version,
// their versions match and their type match.
// If they have zero version, modtime must match.
func (x xlMetaV2VersionHeader) matchesNotStrict(o xlMetaV2VersionHeader) (ok bool) {

const (
	// Mode constants from the USTAR spec:
	// See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html#tag_20_92_13_06
	c_ISUID = 04000 // Set uid
	c_ISGID = 02000 // Set gid
	c_ISVTX = 01000 // Save text (sticky bit)

	// Common Unix mode constants; these are not defined in any common tar standard.
	// Header.FileInfo understands these, but FileInfoHeader will never produce these.
	c_ISDIR  = 040000  // Directory

// 1. object lock config - object lock should have been specified at time of bucket creation. Only default retention settings are imported here.
// 2. Replication config - is omitted from import as remote target credentials are not available from exported data for security reasons.
// 3. lifecycle config - if transition rules are present, tier name needs to have been defined.

    return requireNonNull(values);
  }

  /*
   * The following methods are safe to call as long as the conditions in the *previous* comment are
   * met *and* the index is less than size().
   *
   * (The above explains when these methods are safe from a `nullness` perspective. From an
   * `unchecked` perspective, they're safe because we put only K/V elements into each array.)
   */

  @SuppressWarnings("unchecked")

                session = InternalSession.from(session.withLocalRepository(localRepository));
            }
            this.session = session;
            this.modelBuilderSession = modelBuilder.newSession();
            // Save the ModelBuilderSession for later retrieval by the DefaultConsumerPomBuilder.
            // Use replace(key, null, value) to make sure the *main* session, i.e. the one used

	info, err := context.ImportDir(dir, 0)
	if err != nil {
		if _, nogo := err.(*build.NoGoError); nogo {
			return nil, err
		}
		log.Fatalf("pkg %q, dir %q: ScanDir: %v", name, dir, err)
	}

	// Save tags list first time we see a directory.
	if usePkgCache {
		if _, ok := pkgTags[dir]; !ok {
			pkgTags[dir] = info.AllTags
			key = tagKey(dir, context, info.AllTags)
		}
	}

            profiles.add(profile);
        }
        return profiles;
    }

    private Model interpolateModel(Model model, ModelBuildingRequest request, ModelProblemCollector problems) {
        // save profile activations before interpolation, since they are evaluated with limited scope
        List<Profile> originalProfiles = getProfiles(model);

        Model interpolatedModel =

		// fmt.Printf("CheckRedirect:\n")
		// fmt.Printf("Upcoming: %s %s\n", req.Method, req.URL.String())
		// for i, c := range via {
		// 	fmt.Printf("Sofar %d: %s %s\n", i, c.Method, c.URL.String())
		// }
		// Save the last request in a redirect chain.
		lastReq = req
		// We do not follow redirect back to client application.
		if req.URL.Path == "/oauth_callback" {
			return http.ErrUseLastResponse
		}
		return nil