Request Publisher Flow

graph TB %% External Input PubSub[("PubSub Events Topic
event-pers.push.request-publisher.{mode}.{group}")] %% Main Handler subgraph "Request Publisher Handler" RPH[Request Publisher Handler] Pipeline[Processing Pipeline] subgraph "Pipeline Steps" FetchStep[Fetch Campaign Step] PostTemplatesStep[Post Templates Step] PrepareStep[Prepare Templates Step
conditional if batching] BuildMsgStep[Build Request Message Step] PublishStep[Publish Request Step] end end %% Channel System subgraph "Channel System" Registry[Channel Registry] PushChannel[Push Channel
with Request Processing] end %% External Services subgraph "External Services" PersonalizationService[(Personalization Service)] PushCampaignService[(Push Campaign Service)] TemplateService[(Template Processing)] end %% Publishers & Clients subgraph "Publishers & Clients" PersonalizationClient[Personalization Client] ErrorsPublisher[Errors Publisher
config.ErrorsTopic] subgraph "PubSub Clients" MainClient[Main PubSub Client
GCloudProjectId] PersClient[Personalization Client
PersGCloudProjectId] end end %% Telemetry subgraph "Telemetry & Monitoring" TelemetryResource[Telemetry Resource] MeterProvider[Meter Provider] OpenTelemetry[OpenTelemetry Provider] end %% Output Topics subgraph "Output Topics" PersonalizationTopic[("Personalization Request Topic")] ErrorTopics[("Error Topics")] end %% Flow connections PubSub --> RPH RPH --> Pipeline Pipeline --> FetchStep FetchStep --> PostTemplatesStep PostTemplatesStep --> PrepareStep PrepareStep --> BuildMsgStep BuildMsgStep --> PublishStep %% Channel processing RPH --> Registry Registry --> PushChannel %% External service calls FetchStep --> PushCampaignService PostTemplatesStep --> TemplateService PublishStep --> PersonalizationClient PersonalizationClient --> PersonalizationService PersonalizationService --> PersonalizationTopic %% Error handling FetchStep --> ErrorsPublisher PostTemplatesStep --> ErrorsPublisher PublishStep --> ErrorsPublisher ErrorsPublisher --> ErrorTopics %% Client connections RPH --> MainClient RPH --> PersClient ErrorsPublisher --> MainClient PersonalizationClient --> PersClient %% Telemetry connections RPH --> TelemetryResource TelemetryResource --> MeterProvider MeterProvider --> OpenTelemetry %% Styling classDef handler fill:#fce4ec,stroke:#c2185b,stroke-width:2px classDef pipeline fill:#e3f2fd,stroke:#1976d2,stroke-width:2px classDef channel fill:#e1f5fe,stroke:#01579b,stroke-width:2px classDef service fill:#e8f5e8,stroke:#2e7d32,stroke-width:2px classDef client fill:#f3e5f5,stroke:#4a148c,stroke-width:2px classDef topic fill:#fff3e0,stroke:#ef6c00,stroke-width:2px classDef telemetry fill:#f1f8e9,stroke:#558b2f,stroke-width:2px class RPH,Pipeline handler class FetchStep,PostTemplatesStep,PrepareStep,BuildMsgStep,PublishStep pipeline class Registry,PushChannel channel class PersonalizationService,PushCampaignService,TemplateService service class PersonalizationClient,ErrorsPublisher,MainClient,PersClient client class PubSub,PersonalizationTopic,ErrorTopics topic class TelemetryResource,MeterProvider,OpenTelemetry telemetry

sequenceDiagram participant PS as PubSub participant RPH as Request Publisher Handler participant Pipeline as Processing Pipeline participant Registry as Channel Registry participant PC as Push Channel participant CampaignSvc as Campaign Service participant TemplateBuilder as Template Builder participant PersClient as Personalization Client participant PersService as Personalization Service participant OutTopic as Output Topic PS->>RPH: Batch of event messages RPH->>Pipeline: Execute processing pipeline %% Pipeline execution loop For each message batch group Pipeline->>PC: 1. Fetch Campaign Step PC->>CampaignSvc: FetchCampaign(customerId, campaignId) CampaignSvc->>PC: Campaign metadata Pipeline->>PC: 2. Post Templates Step PC->>TemplateBuilder: BuildPersonalizationTemplates TemplateBuilder->>PC: Templates with fields to personalize PC->>PersClient: PostTemplates(customerId, campaignId, templates) PersClient->>PersService: HTTP POST templates PersService->>PersClient: Template response with hash PersClient->>PC: Hash alt Batch Mode Pipeline->>PC: 3. Prepare Templates Step PC->>PersClient: PrepareTemplates(customerId, campaignId, hash) PersClient->>PersService: HTTP GET prepare PersService->>PersClient: Prepare response PersClient->>PC: Success end Pipeline->>PC: 4. Build Request Message Step PC->>PC: BuildPersonalizationRequestMessage Pipeline->>PC: 5. Publish Request Step PC->>OutTopic: Publish personalization request end alt Processing Errors Pipeline->>RPH: Handle pipeline errors RPH->>PS: Publish to errors topic end RPH->>PS: Acknowledge processed messages

sequenceDiagram participant Handler as Request Publisher Handler participant Registry as Channel Registry participant Channel as Channel Handler
(Push/EmbeddedMessaging) participant CampaignSvc as Campaign Service participant TemplateBuilder as Template Builder participant PersClient as Personalization Client Note over Handler: Processing batch of messages Handler->>Registry: DetermineChannel(message attributes) Registry->>Channel: Return channel instance rect rgb(230, 240, 255) Note over Handler,PersClient: 1. GetCampaign - Fetch campaign metadata Handler->>Channel: GetCampaign(customerId, campaignId) Channel->>CampaignSvc: Fetch campaign data CampaignSvc-->>Channel: Campaign metadata Channel-->>Handler: Campaign data end rect rgb(240, 255, 240) Note over Handler,PersClient: 2. PostTemplates - Create personalization templates Handler->>Channel: Call template processing Channel->>TemplateBuilder: BuildPersonalizationTemplates(campaign) TemplateBuilder-->>Channel: Templates with fields Channel->>PersClient: PostTemplates(customerId, campaignId, templates) PersClient-->>Channel: Template hash Channel-->>Handler: Hash for personalization end alt Batch Mode rect rgb(255, 245, 230) Note over Handler,PersClient: 3. PrepareTemplates - Wait for template preparation Handler->>Channel: PrepareTemplates(customerId, campaignId, hash) Channel->>PersClient: HTTP GET prepare endpoint PersClient-->>Channel: Preparation complete Channel-->>Handler: Success end end rect rgb(255, 240, 245) Note over Handler,PersClient: 4. GetAttributes - Build message attributes Handler->>Channel: GetAttributes(campaignId, hash, messages) Note over Channel: Does NOT include MeCampaignIdAttribute
(added by builder) Channel-->>Handler: Channel-specific attributes end rect rgb(245, 240, 255) Note over Handler,PersClient: 5. BuildMessage & Publish Handler->>Handler: BuildPersonalizationRequestMessage
(adds MeCampaignIdAttribute) Handler->>PersClient: Publish to personalization service end Note over Handler: Message successfully published for personalization