enixdark · September 5, 2022 18:01 · Mar 30, 2015
diff --git a/zero_downtime_reindexing.py b/zero_downtime_reindexing.py
@@ -0,0 +1,54 @@
+from datetime import datetime
+from elasticsearch_dsl import (
+    DocType,
+    String,
+    Integer,
+    Float
+)
+
+
+def _suffix():
+    return datetime.now().strftime("%Y%m%d%H%M%S%f")
+
+
+class Company(DocType):
+    name = String(analyzer='kuromoji')
+    alias = String(analyzer='2gram')
+    languages = String(multi=True)
+    pref = Integer()
+    point = Float()
+
+    class Meta:
+        index = 'company'
+
+
+def reindex():
+    """
+    Elasticsearch Zero Downtime Reindexing using elasticsearch-dsl-py
+    """
+    c = Company().connection
+    alias = Company._doc_type.index
+
+    # If alias does not exists, As first create new index.
+    if not c.indices.exists_alias(alias):
+        index = '%s_%s' % (alias, _suffix())
+        Company.init(index)
+        c.indices.put_alias(alias, index)
+
+    old_index = list(c.indices.get_alias(alias).keys())[0]
+    new_index = '%s_%s' % (alias, _suffix())
+
+    # Create new index to ES
+    Company.init(new_index)
+
+    # Put document to new index from Django model's records
+    dosomething(new_index)
+
+    # Change index through alias.
+    c.indices.put_alias(alias, new_index)
+    c.indices.update_aliases({
+        "actions": [
+            {"remove": {"index": old_index, "alias": alias}},
+            {"add": {"index": new_index, "alias": alias}}
+        ]
+    })