How to modify the TTL of all records set with a ttl of -1 in aerospike?

问题

I want to modify the TTL of all the records that were accidentally set with a 'never expire' TTL (-1 in the client). How would I do that?

回答1:

Just to clarify, setting a TTL of -1 in the client means never expire (equivalent to a default-ttl of 0 in the server's aerospike.conf file), while setting a TTL of 0 in the client means inherit the default-ttl for this namespace.

With Predicate Filtering:

If you're using the Java, C, C# and Go clients the easiest way to identify the records with a void time of 0 would be to use a predicate filter. You would apply a simple record UDF to all the records matched by the predicate filter.

ttl.lua

function set_ttl(rec, to_ttl)
  record.set_ttl(rec, to_ttl)
  aerospike:update(rec)
end

Register the Lua module using AQL:

$ aql
Aerospike Query Client
Version 3.12.0
C Client Version 4.1.4
Copyright 2012-2017 Aerospike. All rights reserved.
aql> register module './ttl.lua'
OK, 1 module added.

Then in the Java app:

Statement stmt = new Statement();
stmt.setNamespace(params.namespace);
stmt.setSetName(params.set);
stmt.setPredExp(
  PredExp.recVoidTime(),
  PredExp.integerValue(0),
  PredExp.integerEqual()
  );

ExecuteTask task = client.execute(params.writePolicy, stmt, "ttl", "set_ttl", Value.IntegerValue(604800));
task.waitTillComplete();

Only using UDFs:

With other clients that don't yet have predicate filtering (Python, PHP, etc), you would do it all through a record UDF that's applied to a scan. The filtering logic would have to live inside the UDF.

ttl.lua

function modify_zero_ttl(rec, to_ttl)
  local rec_ttl = record.ttl(rec)
  if rec_ttl == 0 then
    record.set_ttl(rec, to_ttl)
    aerospike:update(rec)
  end
end

In AQL:

$ aql
Aerospike Query Client
Version 3.12.0
C Client Version 4.1.4
Copyright 2012-2017 Aerospike. All rights reserved.
aql> register module './ttl.lua'
OK, 1 module added.

aql> execute ttl.modify_zero_ttl(604800) on test.foo

来源：https://stackoverflow.com/questions/45193957/how-to-modify-the-ttl-of-all-records-set-with-a-ttl-of-1-in-aerospike