change default gpu_cache_capacity to 4

Former-commit-id: d5a629cb39c58cc82696b6656fe67a1e3270a300

core/conf/server_config.template

@@ -30,6 +30,8 @@ metric_config:
 cache_config:
   cpu_cache_capacity: 16            # GB, CPU memory used for cache
   cpu_cache_threshold: 0.85         # percentage of data that will be kept when cache cleanup is triggered
+  gpu_cache_capacity: 4             # GB, GPU memory used for cache
+  gpu_cache_threshold: 0.85         # percentage of data that will be kept when cache cleanup is triggered
   cache_insert_data: false          # whether to load inserted data into cache
 
 engine_config:

core/src/server/Config.h

@@ -62,7 +62,7 @@ static const char* CONFIG_CACHE = "cache_config";
 static const char* CONFIG_CACHE_CPU_CACHE_CAPACITY = "cpu_cache_capacity";
 static const char* CONFIG_CACHE_CPU_CACHE_CAPACITY_DEFAULT = "16";
 static const char* CONFIG_CACHE_GPU_CACHE_CAPACITY = "gpu_cache_capacity";
-static const char* CONFIG_CACHE_GPU_CACHE_CAPACITY_DEFAULT = "0";
+static const char* CONFIG_CACHE_GPU_CACHE_CAPACITY_DEFAULT = "4";
 static const char* CONFIG_CACHE_CPU_CACHE_THRESHOLD = "cpu_mem_threshold";
 static const char* CONFIG_CACHE_CPU_CACHE_THRESHOLD_DEFAULT = "0.85";
 static const char* CONFIG_CACHE_GPU_CACHE_THRESHOLD = "gpu_mem_threshold";