handle exceptions raised due to cache miss

care/facility/management/commands/load_redis_index.py

@@ -1,3 +1,4 @@
+from django.core.cache import cache
 from django.core.management import BaseCommand
 
 from care.facility.static_data.icd11 import load_icd11_diagnosis
@@ -14,6 +15,14 @@ class Command(BaseCommand):
     help = "Loads static data to redis"
 
     def handle(self, *args, **options):
+        if cache.get("redis_index_loading"):
+            print("Redis Index already loading, skipping")
+            return
+
+        cache.set("redis_index_loading", True, timeout=60 * 5)
+
         load_icd11_diagnosis()
         load_medibase_medicines()
         load_pmjy_packages()
+
+        cache.delete("redis_index_loading")

care/facility/tasks/__init__.py

@@ -4,6 +4,7 @@
 from care.facility.tasks.asset_monitor import check_asset_status
 from care.facility.tasks.cleanup import delete_old_notifications
 from care.facility.tasks.plausible_stats import capture_goals
+from care.facility.tasks.redis_index import load_redis_index
 from care.facility.tasks.summarisation import (
     summarise_district_patient,
     summarise_facility_capacity,
@@ -55,3 +56,8 @@ def setup_periodic_tasks(sender, **kwargs):
         capture_goals.s(),
         name="capture_goals",
     )
+    sender.add_periodic_task(
+        crontab(hour="*", minute="0"),
+        load_redis_index.s(),
+        name="load_redis_index",
+    )

care/facility/tasks/redis_index.py

@@ -0,0 +1,32 @@
+from logging import Logger
+
+from celery import shared_task
+from celery.utils.log import get_task_logger
+from django.core.cache import cache
+
+from care.facility.static_data.icd11 import load_icd11_diagnosis
+from care.facility.static_data.medibase import load_medibase_medicines
+from care.hcx.static_data.pmjy_packages import load_pmjy_packages
+from care.utils.static_data.models.base import index_exists
+
+logger: Logger = get_task_logger(__name__)
+
+
+@shared_task
+def load_redis_index():
+    if cache.get("redis_index_loading"):
+        logger.info("Redis Index already loading, skipping")
+        return
+
+    cache.set("redis_index_loading", True, timeout=60 * 2)
+    logger.info("Loading Redis Index")
+    if index_exists():
+        logger.info("Index already exists, skipping")
+        return
+
+    load_icd11_diagnosis()
+    load_medibase_medicines()
+    load_pmjy_packages()
+
+    cache.delete("redis_index_loading")
+    logger.info("Redis Index Loaded")

care/utils/static_data/models/base.py

@@ -2,9 +2,22 @@
 
 from django.conf import settings
 from redis_om import HashModel, get_redis_connection
+from redis_om.model.migrations.migrator import schema_hash_key
 
 
 class BaseRedisModel(HashModel, ABC):
     class Meta:
         database = get_redis_connection(url=settings.REDIS_URL)
         global_key_prefix = "care_static_data"
+
+
+def index_exists(model: HashModel = None):
+    """
+    Checks the existence of a redisearch index.
+    If no model is passed, it checks for the existence of any index.
+    """
+
+    conn = get_redis_connection(url=settings.REDIS_URL)
+    if model:
+        return conn.exists(schema_hash_key(model.Meta.index_name))
+    return len(conn.execute_command("FT._LIST"))

config/exception_handler.py

@@ -0,0 +1,20 @@
+from celery import current_app
+from django.core.exceptions import ValidationError as DjangoValidationError
+from redis_om.model.model import NotFoundError as RedisModelNotFoundError
+from rest_framework.exceptions import APIException
+from rest_framework.exceptions import ValidationError as DRFValidationError
+from rest_framework.fields import get_error_detail
+from rest_framework.views import exception_handler as drf_exception_handler
+
+
+def exception_handler(exc, context):
+    if isinstance(exc, DjangoValidationError):
+        exc = DRFValidationError(detail={"detail": get_error_detail(exc)[0]})
+
+    elif isinstance(exc, RedisModelNotFoundError):
+        current_app.send_task("care.facility.tasks.redis_index.load_redis_index")
+        exc = APIException(
+            detail={"detail": "Something went wrong, please try after a few seconds."}
+        )
+
+    return drf_exception_handler(exc, context)

config/settings/base.py

@@ -332,6 +332,7 @@
     "PAGE_SIZE": 14,
     "SEARCH_PARAM": "search_text",
     "DEFAULT_SCHEMA_CLASS": "care.utils.schema.AutoSchema",
+    "EXCEPTION_HANDLER": "config.exception_handler.exception_handler",
 }
 
 # drf-spectacular (schema generation)