Glean Upgrade & Migration Skill

Glean Upgrade & Migration

Overview

Glean is an enterprise search platform that indexes documents across SaaS tools via connectors and exposes Search and Indexing APIs. Migrations involve connector schema changes, search API response format updates, and document permission model upgrades. Tracking API versions is critical because Glean's Indexing API enforces document schema validation — adding required fields or changing permission structures in a new version will cause bulk indexing failures and stale search results if connectors are not updated in lockstep.

Version Detection

const GLEAN_BASE = "https://your-domain-be.glean.com/api";

async function detectGleanApiVersion(apiToken: string): Promise<void> {
  // Check indexing API health and version
  const indexRes = await fetch(`${GLEAN_BASE}/index/v1/status`, {
    headers: { Authorization: `Bearer ${apiToken}`, "Content-Type": "application/json" },
  });
  const indexStatus = await indexRes.json();
  console.log(`Indexing API version: ${indexRes.headers.get("x-glean-api-version") ?? "v1"}`);
  console.log(`Connector status: ${JSON.stringify(indexStatus.connectors)}`);

  // Check search API for deprecated query parameters
  const searchRes = await fetch(`${GLEAN_BASE}/client/v1/search`, {
    method: "POST",
    headers: { Authorization: `Bearer ${apiToken}`, "Content-Type": "application/json" },
    body: JSON.stringify({ query: "test", pageSize: 1 }),
  });
  const deprecationHeader = searchRes.headers.get("x-glean-deprecated-params");
  if (deprecationHeader) console.warn(`Deprecated parameters: ${deprecationHeader}`);
}

Migration Checklist

[ ] Review Glean developer changelog for Indexing API schema changes
[ ] Audit custom connectors for deprecated document fields
[ ] Verify objectType definitions match current Glean schema requirements
[ ] Check if new required fields were added to document permission model
[ ] Test search API response parsing — results[].snippets format may change
[ ] Update datasource configuration if connector authentication method changed
[ ] Validate bulk indexing with a small document batch before full re-index
[ ] Check people API for identity resolution field changes
[ ] Update search query syntax if faceted search operators were modified
[ ] Monitor indexing error dashboard for 48 hours post-migration

Schema Migration

// Glean document schema evolved: flat permissions → structured ACL model
interface OldGleanDocument {
  id: string;
  datasource: string;
  title: string;
  body: { mimeType: string; textContent: string };
  permissions: { allowedUsers: string[] };
  updatedAt: string;
}

interface NewGleanDocument {
  id: string;
  datasource: string;
  title: string;
  body: { mimeType: string; textContent: string };
  permissions: {
    allowedUsers: Array<{ email: string; datasourceUserId?: string }>;
    allowedGroups: Array<{ name: string; datasourceGroupId?: string }>;
    allowAnonymousAccess: boolean;
  };
  viewURL: string;
  updatedAt: string;
}

function migrateDocument(old: OldGleanDocument): NewGleanDocument {
  return {
    ...old,
    permissions: {
      allowedUsers: old.permissions.allowedUsers.map((email) => ({ email })),
      allowedGroups: [],
      allowAnonymousAccess: false,
    },
    viewURL: `https://app.example.com/doc/${old.id}`,
  };
}

Rollback Strategy

class GleanIndexClient {
  constructor(
    private token: string,
    private baseUrl: string,
    private apiVersion: "v1" | "v2" = "v2"
  ) {}

  async indexDocuments(docs: any[]): Promise<any> {
    try {
      const res = await fetch(`${this.baseUrl}/index/${this.apiVersion}/indexdocuments`, {
        method: "POST",
        headers: { Authorization: `Bearer ${this.token}`, "Content-Type": "application/json" },
        body: JSON.stringify({ documents: docs }),
      });
      if (!res.ok) throw new Error(`Glean indexing ${res.status}: ${await res.text()}`);
      return await res.json();
    } catch (err) {
      if (this.apiVersion === "v2") {
        console.warn("Falling back to Glean Indexing API v1");
        this.apiVersion = "v1";
        return this.indexDocuments(docs);
      }
      throw err;
    }
  }
}

Error Handling

| Migration Issue | Symptom | Fix | |----------------|---------|-----| | Document schema validation failure | 400 with missing required field: viewURL | Add viewURL to all documents before re-indexing | | Permission model mismatch | Documents indexed but not searchable by expected users | Migrate flat allowedUsers strings to structured user objects | | Connector auth expired | 401 Unauthorized on bulk index | Rotate API token in Glean admin and update connector config | | Search response format changed | Client crashes parsing snippets as string instead of array | Handle both string and Snippet[] return types | | Datasource quota exceeded | 429 during bulk re-index | Implement rate limiting with exponential backoff per Glean docs |

Resources

Next Steps

For CI pipeline integration, see glean-ci-integration.

Agent Skills: Glean Upgrade & Migration

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