Sporadically nil connection in SolidCache::Entry calls

[iJackUA]

I've noticing couple likely connected issue, not regular and with not yet defined stable preconditions.
Also, it's happening inside the code that I run in ActiveJobs (that is managed by SolidQueue 1.0)

# `cache_key` is a string like "entity:f8ef8db0-8ba9-43d0-92c0-ee400986ed20" 
Rails.cache.exist?(cache_key)

sometimes gives an error

undefined method `select_all' for nil (NoMethodError)

          connection.select_all(query, "SolidCache::Entry Load").cast_values(attribute_types).to_h
                    ^^^^^^^^^^^

another call

Rails.cache.write(cache_key, 1, {})

sometimes gives

undefined method `supports_insert_conflict_target?' for nil (NoMethodError)

          connection.supports_insert_conflict_target? ? :key_hash : nil
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

seems like the same root cause - connection became nil under some conditions (dot not know how to refine these conditions yet)

---

config/cache.yml

cache - uses separate database

was using using database: cache initially, tries also with connects_to - the same behavior

default: &default
  connects_to:
    database:
      writing: :cache
      reading: :cache
  store_options:
    max_age: <%= 30.days.to_i %>
    max_size: <%= 256.megabytes %>
    namespace: <%= Rails.env %>
...

---

Env
Ruby 3.3.0
Rails: 7.2.1.1
SolidCache: 1.0.6
MariaDB with master-master replication in Galera Cluster ()

---

Stack traces:

"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/app/models/solid_cache/entry.rb:38:in `block in read_multi'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/activerecord-7.2.1.1/lib/active_record/connection_adapters/abstract/query_cache.rb:143:in `disable_query_cache'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/activerecord-7.2.1.1/lib/active_record/query_cache.rb:30:in `uncached'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/app/models/solid_cache/entry.rb:131:in `without_query_cache'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/app/models/solid_cache/entry.rb:35:in `read_multi'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/app/models/solid_cache/entry.rb:31:in `read'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/lib/solid_cache/store/entries.rb:40:in `block in entry_read'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/lib/solid_cache/store/execution.rb:49:in `setup_instrumentation'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/lib/solid_cache/store/execution.rb:31:in `execute'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/lib/solid_cache/store/connections.rb:39:in `block in with_connection_for'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/lib/solid_cache/connections/unmanaged.rb:17:in `with_connection_for'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/lib/solid_cache/store/connections.rb:38:in `with_connection_for'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/lib/solid_cache/store/connections.rb:68:in `block in reading_key'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/lib/solid_cache/store/failsafe.rb:32:in `failsafe'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/lib/solid_cache/store/connections.rb:67:in `reading_key'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/lib/solid_cache/store/entries.rb:39:in `entry_read'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/lib/solid_cache/store/api.rb:49:in `read_serialized_entry'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/activesupport-7.2.1.1/lib/active_support/cache/strategy/local_cache.rb:130:in `read_serialized_entry'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/lib/solid_cache/store/api.rb:45:in `read_entry'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/activesupport-7.2.1.1/lib/active_support/cache.rb:706:in `block in exist?'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/activesupport-7.2.1.1/lib/active_support/cache.rb:1022:in `block in _instrument'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/activesupport-7.2.1.1/lib/active_support/notifications.rb:210:in `block in instrument'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/activesupport-7.2.1.1/lib/active_support/notifications/instrumenter.rb:58:in `instrument'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/sentry-rails-5.21.0/lib/sentry/rails/tracing.rb:56:in `instrument'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/activesupport-7.2.1.1/lib/active_support/notifications.rb:210:in `instrument'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/activesupport-7.2.1.1/lib/active_support/cache.rb:1021:in `_instrument'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/activesupport-7.2.1.1/lib/active_support/cache.rb:998:in `instrument'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/activesupport-7.2.1.1/lib/active_support/cache.rb:705:in `exist?'", 

"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/app/models/solid_cache/entry.rb:86:in `upsert_unique_by'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/app/models/solid_cache/entry.rb:26:in `block in write_multi'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/activerecord-7.2.1.1/lib/active_record/connection_adapters/abstract/query_cache.rb:143:in `disable_query_cache'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/activerecord-7.2.1.1/lib/active_record/query_cache.rb:30:in `uncached'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/app/models/solid_cache/entry.rb:131:in `without_query_cache'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/app/models/solid_cache/entry.rb:23:in `write_multi'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/app/models/solid_cache/entry.rb:19:in `write'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/lib/solid_cache/store/entries.rb:52:in `block in entry_write'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/lib/solid_cache/store/execution.rb:49:in `setup_instrumentation'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/lib/solid_cache/store/execution.rb:31:in `execute'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/lib/solid_cache/store/connections.rb:39:in `block in with_connection_for'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/lib/solid_cache/connections/unmanaged.rb:17:in `with_connection_for'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/lib/solid_cache/store/connections.rb:38:in `with_connection_for'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/lib/solid_cache/store/connections.rb:85:in `block in writing_key'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/lib/solid_cache/store/failsafe.rb:32:in `failsafe'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/lib/solid_cache/store/connections.rb:84:in `writing_key'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/lib/solid_cache/store/entries.rb:51:in `entry_write'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/solid_cache-1.0.6/lib/solid_cache/store/api.rb:64:in `write_entry'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/activesupport-7.2.1.1/lib/active_support/cache.rb:666:in `block in write'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/activesupport-7.2.1.1/lib/active_support/cache.rb:1022:in `block in _instrument'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/activesupport-7.2.1.1/lib/active_support/notifications.rb:210:in `block in instrument'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/activesupport-7.2.1.1/lib/active_support/notifications/instrumenter.rb:58:in `instrument'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/sentry-rails-5.21.0/lib/sentry/rails/tracing.rb:56:in `instrument'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/activesupport-7.2.1.1/lib/active_support/notifications.rb:210:in `instrument'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/activesupport-7.2.1.1/lib/active_support/cache.rb:1021:in `_instrument'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/activesupport-7.2.1.1/lib/active_support/cache.rb:998:in `instrument'", 
"/PATH_MASK/bundle/ruby/3.3.0/gems/activesupport-7.2.1.1/lib/active_support/cache.rb:664:in `write'"