February 04, 2025

arch42 Stakeholders for Software

Abstract

arch42 has a section to document the stakeholders of the platform. Stakeholders have different roles and expectations when interacting with the platform’s architecture documentation. The purpose of this post to describe a few common roles and how they relate to each other.

Disclaimer

This post is solely informative. Critically think before using any information presented. Learn from it but ultimately make your own decisions at your own risk.

Requirements

A solution architect documenting the roles and expectations of stakeholders for the platform.

Roles

There are many people involved with the platform. Each person has a particular role and expectation with respect to the platform architecture and its documentation. People may have many roles. ChatGPT was initially prompted with “in software development if the analyst owns the what and the architect owns the how, what does the developer own?”. It was then prompted with the follow-ups “what does the tester own?” and “what does the user own?”. Responses were used to describe roles and expectations.

Owner. The owner is expected to provide the platform team decisions about (a) underlying business goals, (b) platform features and functional (business) requirements, and (c) platform architecture and non-functional (quality) requirements.

Analyst. The analyst is expected to provide the platform team with fully documented functional (business) requirements of the platform features in fulfillment of the underlying business goals. The analyst owns the “what” of the platform’s operation and maintains it in the architecture documentation.

Architect. The architect is expected to provide the platform team with fully documented non-functional (quality) requirements of the platform features in fulfillment of the underlying quality goals. The architect owns the “how” of the platform’s operation and maintains it in the architecture documentation.

Developer. The developer is expected to provide the platform team with an implementation of the platform in fulfillment of both the functional (business) and non-functional (quality) requirements specified by the analyst and architect respectively. The developer owns the “do” of the platform’s operation and references the architecture documentation.

Tester. The tester is expected to provide the platform team with quality assurance of the platform in fulfillment of both the functional (business) and non-functional (quality) requirements specified by the analyst and architect respectively. The tester owns the “validate” of the platform’s operation and references the architecture documentation.

User. The user is expected to provide the platform team with feedback on the platform. The user owns the “experience” of the platform’s operation with no direct use of the architecture documentation.

No list like this can be exhaustive, but, for most platforms this is a good list of roles to start with. Update the expectations or add new roles as appropriate for your platform.

Summary

That’s it, enjoy!

References

arc42 Documentation. (n.d.). https://docs.arc42.org/home/

ISO 25010. (n.d.). https://iso25000.com/index.php/en/iso-25000-standards/iso-25010

OpenAI. (2025). ChatGPT (Feb 04 version) [Large language model]. https://chatgpt.com/

arch42 Quality Goals for Software Architects

Abstract

arch42 has a section to document the quality goal decisions of your system or software product. arch42 references the ISO 25010. This a great standard reference for solution architects to focus on the non-functional requirements important to the stakeholders. The purpose of this post is to show the ISO 25010 standard characteristics and sub-characteristics.

Disclaimer

This post is solely informative. Critically think before using any information presented. Learn from it but ultimately make your own decisions at your own risk.

Requirements

A solution architect working with stakeholders to document the 3–5 most important quality goal characteristics for a system or software product.

ISO 25010

Visit ISO 25010 to read more about the characteristics and sub-characteristics for product quality. Table 1 provides a summary. In general, these are all of the “-ility” statements.

Table 1 - ISO 25010 Quality Characteristics

Functional Stability Performance Efficiency Compatibility Interaction Capability Reliability Security Maintainability Flexibility Safety
Functional Completeness

Functional Correctness

Funcational Appropriateness
Time Behavior

Resource Utilization

Capacity
Co-Existence

Interoperability
Appropriateness Recognizability

Learnability

Operability

User Error Protection

User Engagement

Inclusivity

User Assistance

Self-Descriptiveness
Faultlessness

Availability

Fault Tolerance

Recoverability
Confidentiality

Integrity

Non-Repudiation

Accountability

Authenticity

Resistance

Compliance
Modularity

Reusability

Analysability

Modifiability

Testability
Adaptability

Scalability

Installability

Replaceability
Operational Constraint

Risk Identification

Fail Safe

Hazard Warning

Safe Integration

When deciding the quality goals used to architect and evaluate the system or software product, they should be listed as both characteristics and sub-characteristics as shown in Table 1.

Summary

That’s it, enjoy!

References

arc42 Documentation. (n.d.). https://docs.arc42.org/home/

ISO 25010. (n.d.). https://iso25000.com/index.php/en/iso-25000-standards/iso-25010

January 14, 2025

Apache Derby Database Select-for-Update

Abstract

Select-for-update is an SQL feature which I used to use all the time, but it seems like it’s use has fallen out of favor. However, there are valid use cases for it.

My ferris-resiste project is an RSS to email system. The system keeps track of all RSS entries it encounters to prevent emailing duplicates. However, how long do you keep this history of RSS entries? RSS data isn’t 100% reliable, so the system has its own way of determining when to delete RSS entries. Each time an RSS entry is encountered, the date it’s encountered is saved in the database. If an RSS entry isn’t encountered, that date isn’t updated. Deleting RSS entries is then a simple query which use this last encountered date to delete entries older than 6 months. If the RSS feed hasn’t had that RSS entry for the past 6 months, it’s probably safe to assume the system will not encounter it again.

This is a perfect use case for a select-for-update SQL statement. The purpose of this post is to demonstrate how a select-for-update statement works for the Apache Derby database.

Disclaimer

This post is solely informative. Critically think before using any information presented. Learn from it but ultimately make your own decisions at your own risk.

Code

Listing 1 is Java code demonstrating select-for-update for Apache Derby.

Listing 1 - Java select for update code for Apache Derby

public Optional<RssHistory> find(String feedId, String entryId) {
  
  log.info(String.format("Find RSS entry history feedId=\"%s\", entryId=\"%s\"", feedId, entryId));
  
  Optional<RssHistory> retval
    = Optional.empty();

  StringBuilder sp = new StringBuilder();
  sp.append(" select ");
  sp.append("     feed_id, entry_id, published_on, last_found_on ");
  sp.append(" from ");
  sp.append("     rss_entry_history ");
  sp.append(" where ");
  sp.append("     feed_id=? ");
  sp.append("     and ");
  sp.append("     entry_id=? ");
  sp.append(" for update of ");
  sp.append("     last_found_on ");

  PreparedStatement stmt = null;
  ResultSet rs = null;
  try {
    stmt = conn.prepareUpdatableStatement(sp.toString());
    
    stmt.setString(1, feedId);
    stmt.setString(2, entryId);

    rs = stmt.executeQuery();
    if (rs.next()) {
      retval = Optional.of(
        new RssHistory(feedId, feedId, rs.getTimestamp("published_on").toInstant())
      );
      
      rs.updateDate(4, Date.valueOf(LocalDate.now()));
      rs.updateRow();
    }

  } catch (Throwable t) {
    throw new RuntimeException(
      String.format("Problem finding feed entry in history table feedId=\"%s\", entryId=\"%s\", sql=\"%s\""
        , feedId, entryId, sp.toString()
      ), t
    );
  } finally {
    conn.close(stmt, rs);
  }

  return retval;
}

Lines 17,18 These lines make this a select-for-update query. Line 18 specifies the last_found_on field is being updated.

Line 23 Uses the prepareUpdatableStatement() method to get a Statement object.

Line 34 Uses the updateDate() method to set the new value for the last_found_on field.

Line 35 Uses the updateRow() method to save the updated data to the database within the select-for-update and without having to execute a separate update statement.

Summary

That’s it. Pretty simple. I hope you enjoyed learning how to run a select-for-update SQL statement in Apache Derby.