Migrate from a self-managed cluster with a self-signed certificate using remote reindex


Migrate from a self-managed cluster with a self-signed certificate using remote reindexedit

The following instructions show you how to configure remote reindex on Elasticsearch Service from a cluster that uses a self-signed CA.

Let’s assume that the self-managed cluster that uses a self-signed certificate is called Source, and you want to migrate data from Source to Destination on Elasticsearch Service.

Step 1: Create the Source certificate in a bundleedit

  1. Get the self-signed CA on the Source cluster, or extract the certificate from the cluster by running the following command:

    echo quit | openssl s_client -showcerts -servername "$SOURCE_SERVER_NAME" -connect "$SOURCE_SERVER:$PORT" > cacert.pem
  2. Test cecert.pem you have just created with curl, this should return a successful response:

    curl -XGET https://$SOURCE_SERVER:$PORT -u <username>:<password> --cacert cacert.pem
  3. Create the folder my_source_ca to store the file cacert.pem, and compress the folder to my_source_ca.zip.

Both the folder and file names must correspond to the settings configured in Step 4.

Step 2: Upload the zip bundle to your Elasticsearch Service accountedit

To upload your file, follow the steps in the section Add your extension. Enter wildcard * for Version in order to be compatible for all future upgrades, and select A bundle containing dictionary or script as Type.

Step 3: Create a new deployment on Elasticsearch Serviceedit

From the Elasticsearch Service Console create a new deployment. This will be the Destination cluster.

The Destination cluster should be the same or newer version as the Source cluster. If you already have a cluster available, you can skip this step.

Step 4: Enable bundle and add reindex settings on the Desination cluster.edit

  1. From your deployment page, go to the Edit page, click Manage user settings and extensions, select tab Extensions then enable my_source_ca.
  2. Switch tab to User settings, append the following settings to the elasticsearch.yml. This step adds source_server to the reindex.remote.whitelist, points source CA bundle to be trusted by the Destination cluster using the setting reindex.ssl.certificate_authorities.

    reindex.remote.whitelist: ["$SOURCE_SERVER:$PORT"]
    reindex.ssl.certificate_authorities: "/app/config/my_source_ca/cacert.pem"
    reindex.ssl.verification_mode: "full"

    Make sure reindex.remote.whitelist is in an array format. All uploaded bundles will be uncompressed into /app/config/ folder. Ensure the file path corresponds to your uploaded bundle in Step 1. You can optionally set reindex.ssl.verification_mode to full, certificate or none depending on the validity of hostname and the certificate path. More details can be found in reindex setting.

  3. Click Back to the Edit page and scroll to the button of the page to Save changes. This step will restart all Elasticsearch instances.

Step 5: Reindex from remote Source cluster.edit

You can now run reindex on the Elasticsearch Service Destination cluster from Source cluster:

POST _reindex
  "source": {
    "remote": {
      "host": "https://$SOURCE_SERVER:$PORT",
      "username": "username",
      "password": "xxx"
    "index": "my_source_index"
  "dest": {
    "index": "my_dest_index"

If you have many sources to reindex, it’s is generally better to reindex them one at a time and run them in parallel rather than using a glob pattern to pick up multiple sources. Check reindex from multiple sources for more details.