Chnaged Chunk size to 128kb. Add spec.

app/models/ci/job_trace_chunk.rb

@@ -8,7 +8,7 @@ module Ci
 
     default_value_for :data_store, :redis
 
-    CHUNK_SIZE = 32.kilobytes
+    CHUNK_SIZE = 128.kilobytes
     CHUNK_REDIS_TTL = 1.month
 
     enum data_store: {

spec/models/ci/job_trace_chunk_spec.rb

@@ -9,6 +9,12 @@ describe Ci::JobTraceChunk, :clean_gitlab_redis_shared_state do
     described_class.new(job: job, chunk_index: chunk_index, data_store: data_store, raw_data: raw_data)
   end
 
+  describe 'CHUNK_SIZE' do
+    it 'Chunk size can not be changed without special care' do
+      expect(described_class::CHUNK_SIZE).to eq(128.kilobytes)
+    end
+  end
+
   describe '#data' do
     subject { job_trace_chunk.data }