# Migration Guide

This guide provides comprehensive instructions for migrating from other enterprise search systems to Fess. Fess offers robust compatibility layers, import tools, and APIs to facilitate smooth transitions from various search platforms.

## Table of Contents

- [Supported Migration Sources](#supported-migration-sources)
- [Pre-Migration Planning](#pre-migration-planning)
- [Migration Methods](#migration-methods)

The number of existing Gradle properties is already in the double digits. More properties will be added in the future.
Although properties offer the benefit of precise user-side control and support gradual evolution practices, the high number of properties also presents challenges.

The main challenge on the user side is comprehensibility.

                final String thumbnailField = fessConfig.getIndexFieldThumbnail();
                docList.stream().forEach(doc -> {
                    if (!thumbnailManager.offer(doc)) {
                        if (logger.isDebugEnabled()) {
                            logger.debug("Removing {}={} from doc[{}]", thumbnailField, doc.get(thumbnailField),

            labelType.setCreatedTime(now);
            labelType.setUpdatedBy(Constants.SYSTEM_USER);
            labelType.setUpdatedTime(now);
        }
        tagQueue.offer(qName);
    }

    /**
     * SAX event handler called when an XML end element is encountered.
     * Processes the accumulated text content and creates appropriate configuration objects

     *
     * @param msg the error message to add; ignored if null or blank
     */
    public static void addError(final String msg) {
        if (StringUtil.isNotBlank(msg)) {
            errors.offer(msg);
        }
    }

    /**
     * Command-line options container for the crawler application.
     * This class uses args4j annotations to define command-line arguments

`}blockquote({tokens:e}){return`<blockquote>
${this.parser.parse(e)}</blockquote>
`}html({text:e}){return e}def(e){return""}heading({tokens:e,depth:t}){return`<h${t}>${this.parser.parseInline(e)}</h${t}>
`}hr(e){return`<hr>
`}list(e){let t=e.ordered,n=e.start,r="";for(let a=0;a<e.items.length;a++){let o=e.items[a];r+=this.listitem(o)}let i=t?"ol":"ul",s=t&&n!==1?' start="'+n+'"':"";return"<"+i+s+`>
`+r+"</"+i+`>
`}listitem(e){return`<li>${this.parser.parse(e.tokens)}</li>

no-repeat;\n}\n.carousel-control-prev-icon {\n  background-image: escape-svg($carousel-control-prev-icon-bg);\n}\n.carousel-control-next-icon {\n  background-image: escape-svg($carousel-control-next-icon-bg);\n}\n\n\n// Optional indicator pips\n//\n// Add an ordered list with the following class and add a list item for each\n// slide your carousel holds.\n\n.carousel-indicators {\n  position: absolute;\n  right: 0;\n  bottom: 0;\n  left: 0;\n  z-index: 15;\n  display: flex;\n  justify-content: center;\n  padding-left:...

no-repeat;\n}\n.carousel-control-prev-icon {\n  background-image: escape-svg($carousel-control-prev-icon-bg);\n}\n.carousel-control-next-icon {\n  background-image: escape-svg($carousel-control-next-icon-bg);\n}\n\n\n// Optional indicator pips\n//\n// Add an ordered list with the following class and add a list item for each\n// slide your carousel holds.\n\n.carousel-indicators {\n  position: absolute;\n  right: 0;\n  bottom: 0;\n  left: 0;\n  z-index: 15;\n  display: flex;\n  justify-content: center;\n  padding-left:...