diff --git a/src/main/java/com/redislabs/university/RU102J/dao/CapacityDaoRedisImpl.java b/src/main/java/com/redislabs/university/RU102J/dao/CapacityDaoRedisImpl.java
index 8e24d22..8efb2c4 100644
--- a/src/main/java/com/redislabs/university/RU102J/dao/CapacityDaoRedisImpl.java
+++ b/src/main/java/com/redislabs/university/RU102J/dao/CapacityDaoRedisImpl.java
@@ -59,7 +59,13 @@ public CapacityReport getReport(Integer limit) {
     @Override
     public Long getRank(Long siteId) {
         // START Challenge #4
-        return -2L;
+//        return -2L;
         // END Challenge #4
+        
+        String capacityRankingKey = RedisSchema.getCapacityRankingKey();
+        
+        try (Jedis jedis = jedisPool.getResource()) {
+            return jedis.zrevrank(capacityRankingKey, String.valueOf(siteId));
+        }
     }
 }
diff --git a/src/main/java/com/redislabs/university/RU102J/dao/MetricDaoRedisZsetImpl.java b/src/main/java/com/redislabs/university/RU102J/dao/MetricDaoRedisZsetImpl.java
index 72d3cdf..c6e22ca 100644
--- a/src/main/java/com/redislabs/university/RU102J/dao/MetricDaoRedisZsetImpl.java
+++ b/src/main/java/com/redislabs/university/RU102J/dao/MetricDaoRedisZsetImpl.java
@@ -54,8 +54,8 @@ private void insertMetric(Jedis jedis, long siteId, double value, MetricUnit uni
         // END Challenge #2
         
         MeasurementMinute mm = new MeasurementMinute(value, minuteOfDay);
-        
         jedis.zadd(metricKey, minuteOfDay, mm.toString());
+        jedis.expire(metricKey, METRIC_EXPIRATION_SECONDS);
     }
 
     /**
diff --git a/src/main/java/com/redislabs/university/RU102J/dao/SiteStatsDaoRedisImpl.java b/src/main/java/com/redislabs/university/RU102J/dao/SiteStatsDaoRedisImpl.java
index faa8be4..5361bfe 100644
--- a/src/main/java/com/redislabs/university/RU102J/dao/SiteStatsDaoRedisImpl.java
+++ b/src/main/java/com/redislabs/university/RU102J/dao/SiteStatsDaoRedisImpl.java
@@ -83,6 +83,7 @@ private void updateBasic(Jedis jedis, String key, MeterReading reading) {
     // Challenge #3
     private void updateOptimized(Jedis jedis, String key, MeterReading reading) {
         // START Challenge #3
+        // END Challenge #3
         
         String reportingTime = ZonedDateTime.now(ZoneOffset.UTC).toString();
         
@@ -98,8 +99,6 @@ private void updateOptimized(Jedis jedis, String key, MeterReading reading) {
         script.updateIfGreater(multi, key, SiteStats.maxCapacityField, getCurrentCapacity(reading));
         
         multi.exec();
-        
-        // END Challenge #3
     }
 
     private Double getCurrentCapacity(MeterReading reading) {
diff --git a/src/test/java/com/redislabs/university/RU102J/dao/CapacityDaoRedisImplTest.java b/src/test/java/com/redislabs/university/RU102J/dao/CapacityDaoRedisImplTest.java
index 82917b6..f0b635e 100644
--- a/src/test/java/com/redislabs/university/RU102J/dao/CapacityDaoRedisImplTest.java
+++ b/src/test/java/com/redislabs/university/RU102J/dao/CapacityDaoRedisImplTest.java
@@ -71,7 +71,7 @@ public void getReport() {
     }
 
     // Challenge #4
-    @Ignore
+//    @Ignore
     @Test
     public void getRank() {
         CapacityDao dao = new CapacityDaoRedisImpl(jedisPool);