diff --git a/docs/monasca-api-spec.md b/docs/monasca-api-spec.md
index 84c261fe8..27aafc0fe 100644
--- a/docs/monasca-api-spec.md
+++ b/docs/monasca-api-spec.md
@@ -312,7 +312,7 @@ Before using the API, you must first get a valid auth token from Keystone. All A
 A metric is uniquely identified by a name and set of dimensions.
 
 ### Name
-Defines the name of a metric. A name is of type string(100).
+Defines the name of a metric. A name is of type string(255).
 
 ### Dimensions
 A dictionary of (key, value) pairs. The key and value are of type string(255). The first character in the dimension is restricted to the following: `a-z A-Z 0-9 _ / \ $`. 
@@ -710,7 +710,7 @@ None.
 #### Request Body
 Consists of a single metric object or an array of metric objects. A metric has the following properties:
 
-* name (string(100), required) - The name of the metric.
+* name (string(255), required) - The name of the metric.
 * dimensions ({string(255): string(255)}, optional) - A dictionary consisting of (key, value) pairs used to uniquely identify a metric.
 * timestamp (string, required) - The timestamp in seconds from the Epoch.
 * value (float, required) - Value of the metric. Values with base-10 exponents greater than 126 or less than -130 are truncated.
@@ -793,7 +793,7 @@ Get metrics
 None.
 
 #### Query Parameters
-* name (string(100), optional) - A metric name to filter metrics by.
+* name (string(255), optional) - A metric name to filter metrics by.
 * dimensions (string, optional) - A dictionary to filter metrics by specified as a comma separated array of (key, value) pairs as `key1:value1,key2:value2, ...`
 
 #### Request Body
@@ -853,7 +853,7 @@ Get measurements for metrics.
 None.
 
 #### Query Parameters
-* name (string(100), optional) - A metric name to filter metrics by.
+* name (string(255), optional) - A metric name to filter metrics by.
 * dimensions (string, optional) - A dictionary to filter metrics by specified as a comma separated array of (key, value) pairs as `key1:value1,key2:value2, ...`
 * start_time (string, required) - The start time in ISO 8601 combined date and time format in UTC.
 * end_time (string, optional) - The end time in ISO 8601 combined date and time format in UTC.
@@ -877,7 +877,7 @@ Cache-Control: no-cache
 #### Response Body
 Returns a JSON array of measurements objects for each unique metric with the following fields:
 
-* name (string(100)) - A name of a metric.
+* name (string(255)) - A name of a metric.
 * dimensions ({string(255): string(255)}) - The dimensions of a metric.
 * columns (array[string]) - An array of column names corresponding to the columns in measurements.
 * measurements (array[array[]]) - A two dimensional array of measurements for each timestamp.
@@ -938,7 +938,7 @@ Get statistics for metrics.
 None.
 
 #### Query Parameters
-* name (string(100), required) - A metric name to filter metrics by.
+* name (string(255), required) - A metric name to filter metrics by.
 * dimensions (string, optional) - A dictionary to filter metrics by specified as a comma separated array of (key, value) pairs as `key1:value1,key2:value2, ...`
 * statistics (string, required) - A comma separate array of statistics to evaluate. Valid statistics are avg, min, max, sum and count.
 * start_time (string, required) - The start time in ISO 8601 combined date and time format in UTC.
@@ -965,7 +965,7 @@ Cache-Control: no-cache
 #### Response Body
 Returns a JSON array of statistic objects for each unique metric with the following fields:
 
-* name (string(100)) - A name of a metric.
+* name (string(255)) - A name of a metric.
 * dimensions ({string(255): string(255)}) - The dimensions of a metric.
 * columns (array[string]) - An array of column names corresponding to the columns in statistics.
 * statistics (array[array[]]) - A two dimensional array of statistics for each period.
diff --git a/java/src/main/java/monasca/api/app/command/CreateMetricCommand.java b/java/src/main/java/monasca/api/app/command/CreateMetricCommand.java
index c39f0821d..9fbfb1b02 100644
--- a/java/src/main/java/monasca/api/app/command/CreateMetricCommand.java
+++ b/java/src/main/java/monasca/api/app/command/CreateMetricCommand.java
@@ -31,9 +31,10 @@ import monasca.api.resource.exception.Exceptions;
 public class CreateMetricCommand {
   private static final long TIME_2MIN = 120;
   private static final long TIME_2WEEKS = 1209600;
+  public static final int MAX_NAME_LENGTH = 255;
 
   @NotEmpty
-  @Size(min = 1, max = 64)
+  @Size(min = 1, max = MAX_NAME_LENGTH)
   public String name;
   public Map<String, String> dimensions;
   public long timestamp;
diff --git a/java/src/main/java/monasca/api/app/validation/MetricNameValidation.java b/java/src/main/java/monasca/api/app/validation/MetricNameValidation.java
index 9b3a031b7..72be01d2c 100644
--- a/java/src/main/java/monasca/api/app/validation/MetricNameValidation.java
+++ b/java/src/main/java/monasca/api/app/validation/MetricNameValidation.java
@@ -20,6 +20,7 @@ import javax.annotation.Nullable;
 import com.google.common.base.CharMatcher;
 import com.google.common.base.Strings;
 import monasca.common.model.Services;
+import monasca.api.app.command.CreateMetricCommand;
 import monasca.api.resource.exception.Exceptions;
 import com.sun.jersey.spi.container.WebApplication;
 
@@ -47,9 +48,9 @@ public class MetricNameValidation {
     // General validations
     if (Strings.isNullOrEmpty(metricName))
       throw Exceptions.unprocessableEntity("Metric name is required");
-    if (metricName.length() > 64)
-      throw Exceptions.unprocessableEntity("Metric name %s must be 64 characters or less",
-          metricName);
+    if (metricName.length() > CreateMetricCommand.MAX_NAME_LENGTH)
+      throw Exceptions.unprocessableEntity("Metric name %s must be %d characters or less",
+          metricName, CreateMetricCommand.MAX_NAME_LENGTH);
     if (!Services.isReserved(metricName) && !VALID_METRIC_NAME.matcher(metricName).matches())
       throw Exceptions.unprocessableEntity("Metric name %s may only contain: a-z A-Z 0-9 _ - .",
           metricName);
diff --git a/java/src/test/java/monasca/api/resource/MetricResourceTest.java b/java/src/test/java/monasca/api/resource/MetricResourceTest.java
index 7a6ad7996..35c2f3994 100644
--- a/java/src/test/java/monasca/api/resource/MetricResourceTest.java
+++ b/java/src/test/java/monasca/api/resource/MetricResourceTest.java
@@ -168,11 +168,15 @@ public class MetricResourceTest extends AbstractMonApiResourceTest {
   public void shouldErrorOnCreateWithTooLongName() {
     ClientResponse response =
         createResponseFor(new CreateMetricCommand(
+            "1234567890123456789012345678901234567890123456789012345678901234567890" +
+            "1234567890123456789012345678901234567890123456789012345678901234567890" +
+            "1234567890123456789012345678901234567890123456789012345678901234567890" +
+            "1234567890123456789012345678901234567890123456789012345678901234567890" +
             "1234567890123456789012345678901234567890123456789012345678901234567890", dimensions,
             timestamp, 22.0));
 
     ErrorMessages.assertThat(response.getEntity(String.class)).matches("unprocessable_entity", 422,
-        "[name size must be between 1 and 64");
+        String.format("[name size must be between 1 and %d", CreateMetricCommand.MAX_NAME_LENGTH));
   }
 
   public void shouldErrorOnCreateWithReservedService() {