elasticache how to duplicate the configuration group default.redis3.2 in order to change one parameter without writing the 103 unchanged keys

Question

I use AWS elasticache using this parameter group default.redis3.2, as you can see in this cloudformation sample :

"itophubElastiCacheReplicationGroup" : {
  "Type" : "AWS::ElastiCache::ReplicationGroup",
  "Properties" : {
    "ReplicationGroupDescription" : "Hub WebServer redis cache cluster",
    "AutomaticFailoverEnabled" : "false",
    "AutoMinorVersionUpgrade" : "true",
    "CacheNodeType" : "cache.t2.small",
    "CacheParameterGroupName" : "default.redis3.2",
    "CacheSubnetGroupName" :  { "Ref": "cachesubnethubprivatecachesubnetgroup" },
    "Engine" : "redis",
    "EngineVersion" : "3.2.4",
    "NumCacheClusters" : { "Ref" : "ElasticacheRedisNumCacheClusters" },
    "PreferredMaintenanceWindow" : "sun:04:00-sun:05:00",
    "SecurityGroupIds" : [ { "Fn::GetAtt": ["sgpHubCacheSG",  "GroupId"] } ]
  }
},

what I want to achieve is to have more than the default 16 databases, to do so, I have to change the key databases in the parameter group. Since default.redis3.2 is read only, I have to create my own, I want to have every parameters but databases identical to default.redis3.2. It represent 104 parameters, I don't want to copy past each one of them by hand, so :

I'd like to know if there is a way to copy/inherit the parameters of default.redis3.2 created by aws ?

(If possible using cloudformation)

score 1 · Accepted Answer · answered Jun 15 '17 at 12:06

Having no response, I created manually the conf. comparing it to default.redis3.2 every default values was the same, so I ended up changeing only databases.

I created it manually, and then, I've recreated it this way :

"hubElastiCacheParameterGroup" : {
  "Type": "AWS::ElastiCache::ParameterGroup",
  "Properties": {
    "CacheParameterGroupFamily" : "redis3.2",
    "Description" : "parameter group to match itop hub needs",
    "Properties" : {
      "databases": "200"
    }
  }
},

using it here :

"hubElastiCacheReplicationGroup01" : {
  "Type" : "AWS::ElastiCache::ReplicationGroup",
  "Properties" : {
    [...]
    "CacheParameterGroupName" : { "Ref" : "hubElastiCacheParameterGroup" },
    [...]
  }
},

elasticache how to duplicate the configuration group default.redis3.2 in order to change one parameter without writing the 103 unchanged keys

1 Answers1